5 GITHUB REPOS TO CRACK CODING INTERVIEWS
Free - Star & Start Preparing Today!
====================================
1. Coding Interview University (jwasham) - 355K stars
A complete CS study plan to become a software engineer
Best for: full roadmap from zero to interview-ready
https://github.com/jwasham/coding-interview-university
2. System Design Primer (donnemartin) - 356K stars
Learn to design large-scale systems + Anki flashcards
Best for: system design rounds (Amazon, Google, etc.)
https://github.com/donnemartin/system-design-primer
3. Tech Interview Handbook (yangshun) - 140K stars
Curated, to-the-point interview prep for busy engineers
Best for: quick, high-yield revision
https://github.com/yangshun/tech-interview-handbook
4. The Algorithms - Python (TheAlgorithms) - 222K stars
Every important algorithm implemented in Python
Best for: DSA practice & understanding code
https://github.com/TheAlgorithms/Python
5. Interviews (kdn251) - 65K stars
Everything you need to know to get the job
Best for: data structures, algorithms & DP patterns
https://github.com/kdn251/interviews
====================================
SMART PREP PLAN:
Pick ONE roadmap and follow it daily
Solve 2-3 problems every single day
Revise system design before product-company rounds
Push your solutions to GitHub = shows consistency!
====================================
Want ready-made projects with source code for your resume?
https://t.me/Projectwithsourcecodes
Share with your placement batch!
#CodingInterview #DSA #SystemDesign #Placement
#Algorithms #Python #LeetCode #GitHub #OpenSource
#BTech2026 #MCA2026 #BCA2026 #FinalYearProject
#ProjectWithSourceCodes #StudentsOfIndia
Free - Star & Start Preparing Today!
====================================
1. Coding Interview University (jwasham) - 355K stars
A complete CS study plan to become a software engineer
Best for: full roadmap from zero to interview-ready
https://github.com/jwasham/coding-interview-university
2. System Design Primer (donnemartin) - 356K stars
Learn to design large-scale systems + Anki flashcards
Best for: system design rounds (Amazon, Google, etc.)
https://github.com/donnemartin/system-design-primer
3. Tech Interview Handbook (yangshun) - 140K stars
Curated, to-the-point interview prep for busy engineers
Best for: quick, high-yield revision
https://github.com/yangshun/tech-interview-handbook
4. The Algorithms - Python (TheAlgorithms) - 222K stars
Every important algorithm implemented in Python
Best for: DSA practice & understanding code
https://github.com/TheAlgorithms/Python
5. Interviews (kdn251) - 65K stars
Everything you need to know to get the job
Best for: data structures, algorithms & DP patterns
https://github.com/kdn251/interviews
====================================
SMART PREP PLAN:
Pick ONE roadmap and follow it daily
Solve 2-3 problems every single day
Revise system design before product-company rounds
Push your solutions to GitHub = shows consistency!
====================================
Want ready-made projects with source code for your resume?
https://t.me/Projectwithsourcecodes
Share with your placement batch!
#CodingInterview #DSA #SystemDesign #Placement
#Algorithms #Python #LeetCode #GitHub #OpenSource
#BTech2026 #MCA2026 #BCA2026 #FinalYearProject
#ProjectWithSourceCodes #StudentsOfIndia
5 GITHUB REPOS TO LEARN CODING FOR FREE
Star, Learn & Build - No Payment Needed!
====================================
1. freeCodeCamp - 451K stars
Full free curriculum - math, programming & CS from zero
Best for: complete beginners starting their journey
https://github.com/freeCodeCamp/freeCodeCamp
2. Project Based Learning - 273K stars
Curated tutorials to build real apps in any language
Best for: learning by actually building things
https://github.com/practical-tutorials/project-based-learning
3. App Ideas Collection - 95K stars
100+ application ideas to sharpen your coding skills
Best for: when you don't know what to build next
https://github.com/florinpop17/app-ideas
4. Public APIs - 450K stars
A huge list of free APIs for your projects
Best for: adding real data to your apps
https://github.com/public-apis/public-apis
5. 30 Seconds of Code - 128K stars
Short, high-quality code snippets & dev articles
Best for: leveling up your everyday coding skills
https://github.com/Chalarangelo/30-seconds-of-code
====================================
HOW TO ACTUALLY LEARN:
Pick ONE and stay consistent daily
Build a small project from App Ideas
Use a free API to make it real
Push everything to GitHub - build your portfolio!
====================================
Want ready-made projects with source code?
https://t.me/Projectwithsourcecodes
Share with your coding friends!
#LearnToCode #WebDevelopment #Programming #GitHub
#OpenSource #FreeCourse #Python #JavaScript #API
#BTech2026 #MCA2026 #BCA2026 #FinalYearProject
#ProjectWithSourceCodes #StudentsOfIndia
Star, Learn & Build - No Payment Needed!
====================================
1. freeCodeCamp - 451K stars
Full free curriculum - math, programming & CS from zero
Best for: complete beginners starting their journey
https://github.com/freeCodeCamp/freeCodeCamp
2. Project Based Learning - 273K stars
Curated tutorials to build real apps in any language
Best for: learning by actually building things
https://github.com/practical-tutorials/project-based-learning
3. App Ideas Collection - 95K stars
100+ application ideas to sharpen your coding skills
Best for: when you don't know what to build next
https://github.com/florinpop17/app-ideas
4. Public APIs - 450K stars
A huge list of free APIs for your projects
Best for: adding real data to your apps
https://github.com/public-apis/public-apis
5. 30 Seconds of Code - 128K stars
Short, high-quality code snippets & dev articles
Best for: leveling up your everyday coding skills
https://github.com/Chalarangelo/30-seconds-of-code
====================================
HOW TO ACTUALLY LEARN:
Pick ONE and stay consistent daily
Build a small project from App Ideas
Use a free API to make it real
Push everything to GitHub - build your portfolio!
====================================
Want ready-made projects with source code?
https://t.me/Projectwithsourcecodes
Share with your coding friends!
#LearnToCode #WebDevelopment #Programming #GitHub
#OpenSource #FreeCourse #Python #JavaScript #API
#BTech2026 #MCA2026 #BCA2026 #FinalYearProject
#ProjectWithSourceCodes #StudentsOfIndia
5 GITHUB REPOS TO MASTER PYTHON!
Zero to Pro - Projects - Interview Ready
Python is the #1 language for AI, data science
& automation. These free GitHub repos take you
from beginner to confident coder. Links below!
#Python #LearnPython #Programming #GitHub
#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia
Zero to Pro - Projects - Interview Ready
Python is the #1 language for AI, data science
& automation. These free GitHub repos take you
from beginner to confident coder. Links below!
#Python #LearnPython #Programming #GitHub
#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia
ā¤1
5 GITHUB REPOS TO MASTER PYTHON
Free - Star, Learn & Build!
====================================
1. Awesome Python (vinta) - 309K stars
A curated list of the best Python frameworks, libraries & tools
Best for: discovering the right tool for any project
https://github.com/vinta/awesome-python
2. Python-100-Days (jackfrued) - 184K stars
Go from newbie to master in 100 days, step by step
Best for: a complete structured learning path
https://github.com/jackfrued/Python-100-Days
3. 30 Days of Python (Asabeneh) - 68K stars
A 30-day beginner-friendly Python challenge
Best for: building a daily coding habit
https://github.com/Asabeneh/30-Days-Of-Python
4. Python Patterns (faif) - 42K stars
Design patterns & idioms implemented in Python
Best for: writing clean, professional code
https://github.com/faif/python-patterns
5. Python Examples (geekcomputers) - 35K stars
Hundreds of small, practical Python scripts
Best for: learning by reading real, simple code
https://github.com/geekcomputers/Python
====================================
SMART PYTHON PLAN:
Follow ONE path daily (100 Days or 30 Days)
Recreate small scripts from Python Examples
Learn patterns once you know the basics
Push all practice code to GitHub = portfolio!
====================================
Want ready-made Python projects with source code?
https://t.me/Projectwithsourcecodes
Share with your coding friends!
#Python #LearnPython #Programming #DataScience
#Automation #GitHub #OpenSource #Coding
#BTech2026 #MCA2026 #BCA2026 #FinalYearProject
#ProjectWithSourceCodes #StudentsOfIndia
Free - Star, Learn & Build!
====================================
1. Awesome Python (vinta) - 309K stars
A curated list of the best Python frameworks, libraries & tools
Best for: discovering the right tool for any project
https://github.com/vinta/awesome-python
2. Python-100-Days (jackfrued) - 184K stars
Go from newbie to master in 100 days, step by step
Best for: a complete structured learning path
https://github.com/jackfrued/Python-100-Days
3. 30 Days of Python (Asabeneh) - 68K stars
A 30-day beginner-friendly Python challenge
Best for: building a daily coding habit
https://github.com/Asabeneh/30-Days-Of-Python
4. Python Patterns (faif) - 42K stars
Design patterns & idioms implemented in Python
Best for: writing clean, professional code
https://github.com/faif/python-patterns
5. Python Examples (geekcomputers) - 35K stars
Hundreds of small, practical Python scripts
Best for: learning by reading real, simple code
https://github.com/geekcomputers/Python
====================================
SMART PYTHON PLAN:
Follow ONE path daily (100 Days or 30 Days)
Recreate small scripts from Python Examples
Learn patterns once you know the basics
Push all practice code to GitHub = portfolio!
====================================
Want ready-made Python projects with source code?
https://t.me/Projectwithsourcecodes
Share with your coding friends!
#Python #LearnPython #Programming #DataScience
#Automation #GitHub #OpenSource #Coding
#BTech2026 #MCA2026 #BCA2026 #FinalYearProject
#ProjectWithSourceCodes #StudentsOfIndia
5 LATEST FINAL YEAR PROJECTS!
Fresh on UpdateGadh - Full Source Code + Docs
Newly added, ready-to-submit projects for
BCA / MCA / B.Tech / M.Tech students. PHP, Python,
Django & AI. Direct links below!
#FinalYearProject #SourceCode #PHP #Python #AI
#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia
Fresh on UpdateGadh - Full Source Code + Docs
Newly added, ready-to-submit projects for
BCA / MCA / B.Tech / M.Tech students. PHP, Python,
Django & AI. Direct links below!
#FinalYearProject #SourceCode #PHP #Python #AI
#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia
5 LATEST FINAL YEAR PROJECTS - UPDATEGADH
With Full Source Code + Documentation
====================================
1. Railway Management System - PHP & MySQL
Book, manage & track trains - a classic, impressive DBMS project
https://updategadh.com/railway-management-system-in-php-and-mysql/
2. Agentic RAG AI System - Python
Advanced 2026 AI architecture - build your own agentic RAG system
https://updategadh.com/agentic-rag-ai-system-using-python/
3. AI Online Examination System with Face Detection - PHP & MySQL
Secure online exams with AI proctoring & face detection
https://updategadh.com/online-examination-system-with-face-detection/
4. Real-Time Medical Queue & Appointment System - Django
MediQueue - live patient queue & appointment booking
https://updategadh.com/appointment-system-with-django/
5. Online Examination System - PHP
Complete exam portal for BCA/MCA/B.Tech/M.Tech with source code
https://updategadh.com/online-examination-system-in-php-with-source-code/
====================================
Each project includes:
- Complete source code
- Documentation
- Setup guide & support
====================================
More ready-made projects with source code:
https://t.me/Projectwithsourcecodes
Share with your final-year batch!
#FinalYearProject #SourceCode #PHP #MySQL #Python
#Django #AI #RAG #DBMS #WebDevelopment #MiniProject
#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia
With Full Source Code + Documentation
====================================
1. Railway Management System - PHP & MySQL
Book, manage & track trains - a classic, impressive DBMS project
https://updategadh.com/railway-management-system-in-php-and-mysql/
2. Agentic RAG AI System - Python
Advanced 2026 AI architecture - build your own agentic RAG system
https://updategadh.com/agentic-rag-ai-system-using-python/
3. AI Online Examination System with Face Detection - PHP & MySQL
Secure online exams with AI proctoring & face detection
https://updategadh.com/online-examination-system-with-face-detection/
4. Real-Time Medical Queue & Appointment System - Django
MediQueue - live patient queue & appointment booking
https://updategadh.com/appointment-system-with-django/
5. Online Examination System - PHP
Complete exam portal for BCA/MCA/B.Tech/M.Tech with source code
https://updategadh.com/online-examination-system-in-php-with-source-code/
====================================
Each project includes:
- Complete source code
- Documentation
- Setup guide & support
====================================
More ready-made projects with source code:
https://t.me/Projectwithsourcecodes
Share with your final-year batch!
#FinalYearProject #SourceCode #PHP #MySQL #Python
#Django #AI #RAG #DBMS #WebDevelopment #MiniProject
#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia
https://updategadh.com/
AI-Based Smart Energy Consumption Analyzer and Optimization
The AI-Based Smart Energy Consumption Analyzer is an intelligent .Are you looking for a final year project on Artificial Intelligence and Machine
ā” AI-Based Smart Energy Consumption Analyzer
AI + Machine Learning project that helps predict energy consumption, estimate electricity bills, and provide smart energy-saving recommendations. š¤š
š ļø Tech: Python ⢠XGBoost ⢠Flask ⢠Groq AI
š Read More: "https://updategadh.com/ai-based-smart-energy-consumption/
#AI #MachineLearning #Python #FinalYearProject #DataScience #XGBoost
AI + Machine Learning project that helps predict energy consumption, estimate electricity bills, and provide smart energy-saving recommendations. š¤š
š ļø Tech: Python ⢠XGBoost ⢠Flask ⢠Groq AI
š Read More: "https://updategadh.com/ai-based-smart-energy-consumption/
#AI #MachineLearning #Python #FinalYearProject #DataScience #XGBoost
š Coding Interview Questions with Answers (Part :-1)
1ļøā£8ļøā£9ļøā£ Check if Two Strings are Anagrams
š Same characters, same frequency, different order.
python
s1, s2 = "listen", "silent"
print(sorted(s1) == sorted(s2))
ā± O(n log n)
1ļøā£9ļøā£0ļøā£ Factorial of a Number
š Product of all integers from 1 to n.
python
def factorial(n):
result = 1
for i in range(1, n+1):
result *= i
return result
ā± O(n)
1ļøā£9ļøā£1ļøā£ Check if a Number is Prime
š Divisible only by 1 and itself.
python
def is_prime(n):
if n < 2: return False
for i in range(2, int(n**0.5)+1):
if n % i == 0: return False
return True
ā± O(ān)
1ļøā£9ļøā£2ļøā£ Fibonacci Sequence
š Sum of the two preceding numbers.
python
def fibonacci(n):
seq = [0, 1]
while len(seq) < n:
seq.append(seq[-1]+seq[-2])
return seq[:n]
ā± O(n)
1ļøā£9ļøā£3ļøā£ GCD of Two Numbers
š Euclidean algorithm.
python
def gcd(a, b):
while b:
a, b = b, a % b
return a
ā± O(log(min(a,b)))
1ļøā£9ļøā£4ļøā£ Frequency of Elements
š Count occurrences using Counter.
python
from collections import Counter
print(Counter([1,2,2,3,3,3]))
ā± O(n)
1ļøā£9ļøā£5ļøā£ Rotate Array by K Positions
š Slice and swap.
python
def rotate(arr, k):
k = k % len(arr)
return arr[-k:] + arr[:-k]
ā± O(n)
š¬ Save this for your next interview prep! Which topic should Part 2 cover ā Linked Lists, Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
1ļøā£8ļøā£9ļøā£ Check if Two Strings are Anagrams
š Same characters, same frequency, different order.
python
s1, s2 = "listen", "silent"
print(sorted(s1) == sorted(s2))
ā± O(n log n)
1ļøā£9ļøā£0ļøā£ Factorial of a Number
š Product of all integers from 1 to n.
python
def factorial(n):
result = 1
for i in range(1, n+1):
result *= i
return result
ā± O(n)
1ļøā£9ļøā£1ļøā£ Check if a Number is Prime
š Divisible only by 1 and itself.
python
def is_prime(n):
if n < 2: return False
for i in range(2, int(n**0.5)+1):
if n % i == 0: return False
return True
ā± O(ān)
1ļøā£9ļøā£2ļøā£ Fibonacci Sequence
š Sum of the two preceding numbers.
python
def fibonacci(n):
seq = [0, 1]
while len(seq) < n:
seq.append(seq[-1]+seq[-2])
return seq[:n]
ā± O(n)
1ļøā£9ļøā£3ļøā£ GCD of Two Numbers
š Euclidean algorithm.
python
def gcd(a, b):
while b:
a, b = b, a % b
return a
ā± O(log(min(a,b)))
1ļøā£9ļøā£4ļøā£ Frequency of Elements
š Count occurrences using Counter.
python
from collections import Counter
print(Counter([1,2,2,3,3,3]))
ā± O(n)
1ļøā£9ļøā£5ļøā£ Rotate Array by K Positions
š Slice and swap.
python
def rotate(arr, k):
k = k % len(arr)
return arr[-k:] + arr[:-k]
ā± O(n)
š¬ Save this for your next interview prep! Which topic should Part 2 cover ā Linked Lists, Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
š Coding Interview Questions with Answers (Part:-2)
1ļøā£9ļøā£6ļøā£ Find All Pairs with a Given Sum
š Use a set to track complements while scanning.
python
def find_pairs(arr, target):
seen, pairs = set(), []
for num in arr:
complement = target - num
if complement in seen:
pairs.append((complement, num))
seen.add(num)
return pairs
print(find_pairs([2,4,3,7,1,5], 7))
ā± O(n)
1ļøā£9ļøā£7ļøā£ Check if an Array is Sorted
š Compare each element with the next one.
python
def is_sorted(arr):
return all(arr[i] <= arr[i+1] for i in range(len(arr)-1))
print(is_sorted([1,2,3,4,5]))
ā± O(n)
1ļøā£9ļøā£8ļøā£ Find the Intersection of Two Arrays
š Use set intersection to find common elements.
python
a = [1,2,3,4]
b = [3,4,5,6]
print(list(set(a) & set(b)))
ā± O(n+m)
1ļøā£9ļøā£9ļøā£ Count Vowels in a String
š Loop through and check membership in a vowel set.
python
def count_vowels(s):
return sum(1 for ch in s.lower() if ch in "aeiou")
print(count_vowels("Hello World"))
ā± O(n)
2ļøā£0ļøā£0ļøā£ Check if a Number is a Power of Two
š A power of two has exactly one bit set ā use bitwise AND trick.
python
def is_power_of_two(n):
return n > 0 and (n & (n-1)) == 0
print(is_power_of_two(16))
ā± O(1)
2ļøā£0ļøā£1ļøā£ Flatten a Nested List
š Recursively unpack nested lists into a single flat list.
python
def flatten(lst):
result = []
for item in lst:
if isinstance(item, list):
result.extend(flatten(item))
else:
result.append(item)
return result
print(flatten([1, [2, 3, [4, 5]], 6]))
ā± O(n)
2ļøā£0ļøā£2ļøā£ Find the First Non-Repeating Character
š Use a frequency count, then find the first with count 1.
python
from collections import Counter
def first_unique(s):
freq = Counter(s)
for ch in s:
if freq[ch] == 1:
return ch
return None
print(first_unique("swiss"))
ā± O(n)
š¬ Bookmark this for your next interview prep! Should Part 3 dive into Linked Lists, Binary Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
1ļøā£9ļøā£6ļøā£ Find All Pairs with a Given Sum
š Use a set to track complements while scanning.
python
def find_pairs(arr, target):
seen, pairs = set(), []
for num in arr:
complement = target - num
if complement in seen:
pairs.append((complement, num))
seen.add(num)
return pairs
print(find_pairs([2,4,3,7,1,5], 7))
ā± O(n)
1ļøā£9ļøā£7ļøā£ Check if an Array is Sorted
š Compare each element with the next one.
python
def is_sorted(arr):
return all(arr[i] <= arr[i+1] for i in range(len(arr)-1))
print(is_sorted([1,2,3,4,5]))
ā± O(n)
1ļøā£9ļøā£8ļøā£ Find the Intersection of Two Arrays
š Use set intersection to find common elements.
python
a = [1,2,3,4]
b = [3,4,5,6]
print(list(set(a) & set(b)))
ā± O(n+m)
1ļøā£9ļøā£9ļøā£ Count Vowels in a String
š Loop through and check membership in a vowel set.
python
def count_vowels(s):
return sum(1 for ch in s.lower() if ch in "aeiou")
print(count_vowels("Hello World"))
ā± O(n)
2ļøā£0ļøā£0ļøā£ Check if a Number is a Power of Two
š A power of two has exactly one bit set ā use bitwise AND trick.
python
def is_power_of_two(n):
return n > 0 and (n & (n-1)) == 0
print(is_power_of_two(16))
ā± O(1)
2ļøā£0ļøā£1ļøā£ Flatten a Nested List
š Recursively unpack nested lists into a single flat list.
python
def flatten(lst):
result = []
for item in lst:
if isinstance(item, list):
result.extend(flatten(item))
else:
result.append(item)
return result
print(flatten([1, [2, 3, [4, 5]], 6]))
ā± O(n)
2ļøā£0ļøā£2ļøā£ Find the First Non-Repeating Character
š Use a frequency count, then find the first with count 1.
python
from collections import Counter
def first_unique(s):
freq = Counter(s)
for ch in s:
if freq[ch] == 1:
return ch
return None
print(first_unique("swiss"))
ā± O(n)
š¬ Bookmark this for your next interview prep! Should Part 3 dive into Linked Lists, Binary Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
š Coding Interview Questions with Answers (Part 3)
2ļøā£0ļøā£3ļøā£ Find the Union of Two Arrays
š Combine both arrays and remove duplicates.
python
a = [1,2,3,4]
b = [3,4,5,6]
print(list(set(a) | set(b)))
ā± O(n+m)
2ļøā£0ļøā£4ļøā£ Check if a String Contains Only Digits
š Use the built-in isdigit() method.
python
s = "12345"
print(s.isdigit())
ā± O(n)
2ļøā£0ļøā£5ļøā£ Find the Sum of Digits of a Number
š Repeatedly extract the last digit and add it up.
python
def sum_of_digits(n):
total = 0
while n > 0:
total += n % 10
n //= 10
return total
print(sum_of_digits(12345))
ā± O(log n)
2ļøā£0ļøā£6ļøā£ Reverse an Integer
š Convert to string, reverse, convert back ā or use math.
python
def reverse_int(n):
sign = -1 if n < 0 else 1
n = abs(n)
reversed_num = int(str(n)[::-1])
return sign * reversed_num
print(reverse_int(-12345))
ā± O(log n)
2ļøā£0ļøā£7ļøā£ Check if a String is a Subsequence of Another
š Use two pointers to compare characters in order.
python
def is_subsequence(s, t):
it = iter(t)
return all(ch in it for ch in s)
print(is_subsequence("abc", "ahbgdc"))
ā± O(n)
2ļøā£0ļøā£8ļøā£ Find the Maximum Product of Two Numbers in an Array
š Sort and multiply the two largest values.
python
def max_product(arr):
arr.sort()
return arr[-1] * arr[-2]
print(max_product([1,5,3,9,2]))
ā± O(n log n)
2ļøā£0ļøā£9ļøā£ Find All Permutations of a String
š Use recursion or the itertools.permutations function.
python
from itertools import permutations
s = "abc"
perms = ["".join(p) for p in permutations(s)]
print(perms)
ā± O(n!)
š¬ Save this for your next interview prep! Should Part 4 cover Linked Lists, Binary Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
2ļøā£0ļøā£3ļøā£ Find the Union of Two Arrays
š Combine both arrays and remove duplicates.
python
a = [1,2,3,4]
b = [3,4,5,6]
print(list(set(a) | set(b)))
ā± O(n+m)
2ļøā£0ļøā£4ļøā£ Check if a String Contains Only Digits
š Use the built-in isdigit() method.
python
s = "12345"
print(s.isdigit())
ā± O(n)
2ļøā£0ļøā£5ļøā£ Find the Sum of Digits of a Number
š Repeatedly extract the last digit and add it up.
python
def sum_of_digits(n):
total = 0
while n > 0:
total += n % 10
n //= 10
return total
print(sum_of_digits(12345))
ā± O(log n)
2ļøā£0ļøā£6ļøā£ Reverse an Integer
š Convert to string, reverse, convert back ā or use math.
python
def reverse_int(n):
sign = -1 if n < 0 else 1
n = abs(n)
reversed_num = int(str(n)[::-1])
return sign * reversed_num
print(reverse_int(-12345))
ā± O(log n)
2ļøā£0ļøā£7ļøā£ Check if a String is a Subsequence of Another
š Use two pointers to compare characters in order.
python
def is_subsequence(s, t):
it = iter(t)
return all(ch in it for ch in s)
print(is_subsequence("abc", "ahbgdc"))
ā± O(n)
2ļøā£0ļøā£8ļøā£ Find the Maximum Product of Two Numbers in an Array
š Sort and multiply the two largest values.
python
def max_product(arr):
arr.sort()
return arr[-1] * arr[-2]
print(max_product([1,5,3,9,2]))
ā± O(n log n)
2ļøā£0ļøā£9ļøā£ Find All Permutations of a String
š Use recursion or the itertools.permutations function.
python
from itertools import permutations
s = "abc"
perms = ["".join(p) for p in permutations(s)]
print(perms)
ā± O(n!)
š¬ Save this for your next interview prep! Should Part 4 cover Linked Lists, Binary Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
š Coding Interview Questions with Answers (Part 4)
2ļøā£1ļøā£0ļøā£ Find the Longest Word in a String
š Split the string into words and track the longest one.
ā± O(n)
2ļøā£1ļøā£1ļøā£ Check if Two Arrays are Equal (Same Elements, Any Order)
š Compare sorted versions of both arrays.
ā± O(n log n)
2ļøā£1ļøā£2ļøā£ Find the Kth Largest Element in an Array
š Sort the array and pick the element at index -k.
ā± O(n log n)
2ļøā£1ļøā£3ļøā£ Convert a Decimal Number to Binary
š Use Python's built-in
ā± O(log n)
2ļøā£1ļøā£4ļøā£ Check if a Number is an Armstrong Number
š Sum of each digit raised to the power of digit count equals the number.
ā± O(log n)
2ļøā£1ļøā£5ļøā£ Find the Common Elements Between Two Arrays (With Duplicates)
š Use Counter intersection to preserve duplicate counts.
ā± O(n+m)
2ļøā£1ļøā£6ļøā£ Check for Balanced Parentheses
š Use a stack to match opening and closing brackets.
ā± O(n)
š¬ Save this for your next interview prep! Should Part 5 cover Linked Lists, Binary Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
2ļøā£1ļøā£0ļøā£ Find the Longest Word in a String
š Split the string into words and track the longest one.
def longest_word(s):
words = s.split()
return max(words, key=len)
print(longest_word("The quick brown fox jumped"))
ā± O(n)
2ļøā£1ļøā£1ļøā£ Check if Two Arrays are Equal (Same Elements, Any Order)
š Compare sorted versions of both arrays.
a = [1,2,3]
b = [3,2,1]
print(sorted(a) == sorted(b))
ā± O(n log n)
2ļøā£1ļøā£2ļøā£ Find the Kth Largest Element in an Array
š Sort the array and pick the element at index -k.
def kth_largest(arr, k):
return sorted(arr)[-k]
print(kth_largest([3,2,1,5,6,4], 2))
ā± O(n log n)
2ļøā£1ļøā£3ļøā£ Convert a Decimal Number to Binary
š Use Python's built-in
bin() function.n = 42
print(bin(n)[2:])
ā± O(log n)
2ļøā£1ļøā£4ļøā£ Check if a Number is an Armstrong Number
š Sum of each digit raised to the power of digit count equals the number.
def is_armstrong(n):
digits = str(n)
power = len(digits)
return n == sum(int(d)**power for d in digits)
print(is_armstrong(153))
ā± O(log n)
2ļøā£1ļøā£5ļøā£ Find the Common Elements Between Two Arrays (With Duplicates)
š Use Counter intersection to preserve duplicate counts.
from collections import Counter
a = [1,2,2,3]
b = [2,2,3,4]
common = list((Counter(a) & Counter(b)).elements())
print(common)
ā± O(n+m)
2ļøā£1ļøā£6ļøā£ Check for Balanced Parentheses
š Use a stack to match opening and closing brackets.
def is_balanced(s):
stack = []
pairs = {')':'(', ']':'[', '}':'{'}
for ch in s:
if ch in "([{":
stack.append(ch)
elif ch in ")]}":
if not stack or stack.pop() != pairs[ch]:
return False
return not stack
print(is_balanced("{[()]}"))
ā± O(n)
š¬ Save this for your next interview prep! Should Part 5 cover Linked Lists, Binary Trees, or Sorting Algorithms? š
#coding #interview #python #programming #softwareengineer #dsa
š Coding Interview Questions with Answers (Part 5)
2ļøā£1ļøā£7ļøā£ Find the Middle Element of a Linked List
š Use the slow-fast pointer technique ā fast moves 2x speed of slow.
ā± O(n)
2ļøā£1ļøā£8ļøā£ Reverse a Linked List
š Iteratively reverse the
ā± O(n)
2ļøā£1ļøā£9ļøā£ Detect a Cycle in a Linked List
š Floyd's cycle detection ā if fast catches slow, there's a loop.
ā± O(n)
2ļøā£2ļøā£0ļøā£ Merge Two Sorted Linked Lists
š Compare nodes from both lists and link the smaller one each time.
ā± O(n+m)
2ļøā£2ļøā£1ļøā£ Remove the Nth Node from the End of a Linked List
š Use two pointers with a gap of n between them.
ā± O(n)
2ļøā£2ļøā£2ļøā£ Check if a Linked List is a Palindrome
š Reverse the second half and compare it with the first half.
ā± O(n)
2ļøā£2ļøā£3ļøā£ Find the Intersection Point of Two Linked Lists
š Traverse both lists, switching heads when reaching the end, so paths align.
ā± O(n+m)
š¬ Save this for your next interview prep! Should Part 6 cover Binary Trees, Sorting Algorithms, or Stacks & Queues? š
#coding #interview #python #programming #softwareengineer #dsa
2ļøā£1ļøā£7ļøā£ Find the Middle Element of a Linked List
š Use the slow-fast pointer technique ā fast moves 2x speed of slow.
class Node:
def __init__(self, data):
self.data = data
self.next = None
def find_middle(head):
slow = fast = head
while fast and fast.next:
slow = slow.next
fast = fast.next.next
return slow.data
ā± O(n)
2ļøā£1ļøā£8ļøā£ Reverse a Linked List
š Iteratively reverse the
next pointer of each node.def reverse_list(head):
prev = None
curr = head
while curr:
nxt = curr.next
curr.next = prev
prev = curr
curr = nxt
return prev
ā± O(n)
2ļøā£1ļøā£9ļøā£ Detect a Cycle in a Linked List
š Floyd's cycle detection ā if fast catches slow, there's a loop.
def has_cycle(head):
slow = fast = head
while fast and fast.next:
slow = slow.next
fast = fast.next.next
if slow == fast:
return True
return False
ā± O(n)
2ļøā£2ļøā£0ļøā£ Merge Two Sorted Linked Lists
š Compare nodes from both lists and link the smaller one each time.
def merge_lists(l1, l2):
dummy = Node(0)
tail = dummy
while l1 and l2:
if l1.data < l2.data:
tail.next, l1 = l1, l1.next
else:
tail.next, l2 = l2, l2.next
tail = tail.next
tail.next = l1 or l2
return dummy.next
ā± O(n+m)
2ļøā£2ļøā£1ļøā£ Remove the Nth Node from the End of a Linked List
š Use two pointers with a gap of n between them.
def remove_nth_from_end(head, n):
dummy = Node(0)
dummy.next = head
fast = slow = dummy
for _ in range(n):
fast = fast.next
while fast.next:
fast = fast.next
slow = slow.next
slow.next = slow.next.next
return dummy.next
ā± O(n)
2ļøā£2ļøā£2ļøā£ Check if a Linked List is a Palindrome
š Reverse the second half and compare it with the first half.
def is_palindrome(head):
vals = []
while head:
vals.append(head.data)
head = head.next
return vals == vals[::-1]
ā± O(n)
2ļøā£2ļøā£3ļøā£ Find the Intersection Point of Two Linked Lists
š Traverse both lists, switching heads when reaching the end, so paths align.
def get_intersection(headA, headB):
a, b = headA, headB
while a != b:
a = a.next if a else headB
b = b.next if b else headA
return a
ā± O(n+m)
š¬ Save this for your next interview prep! Should Part 6 cover Binary Trees, Sorting Algorithms, or Stacks & Queues? š
#coding #interview #python #programming #softwareengineer #dsa
š Coding Interview Questions with Answers (Part 6)
2ļøā£2ļøā£4ļøā£ Find the Height of a Binary Tree
š Recursively find the max depth of left and right subtrees.
ā± O(n)
2ļøā£2ļøā£5ļøā£ Perform an Inorder Traversal of a Binary Tree
š Visit left subtree, then root, then right subtree.
ā± O(n)
2ļøā£2ļøā£6ļøā£ Perform a Level Order Traversal (BFS) of a Binary Tree
š Use a queue to visit nodes level by level.
ā± O(n)
2ļøā£2ļøā£7ļøā£ Check if a Binary Tree is a Valid BST
š Recursively verify each node falls within a valid min/max range.
ā± O(n)
2ļøā£2ļøā£8ļøā£ Find the Lowest Common Ancestor in a BST
š Traverse down; split point where paths diverge is the LCA.
ā± O(h)
2ļøā£2ļøā£9ļøā£ Check if Two Binary Trees are Identical
š Compare values and recursively check both subtrees.
ā± O(n)
2ļøā£3ļøā£0ļøā£ Find the Diameter of a Binary Tree
š The longest path between any two nodes ā may or may not pass through root.
ā± O(n)
š¬ Save this for your next interview prep! Should Part 7 cover Sorting Algorithms, Stacks & Queues, or Graphs? š
#coding #interview #python #programming #softwareengineer #dsa
2ļøā£2ļøā£4ļøā£ Find the Height of a Binary Tree
š Recursively find the max depth of left and right subtrees.
class Node:
def __init__(self, data):
self.data = data
self.left = None
self.right = None
def tree_height(root):
if not root:
return 0
return 1 + max(tree_height(root.left), tree_height(root.right))
ā± O(n)
2ļøā£2ļøā£5ļøā£ Perform an Inorder Traversal of a Binary Tree
š Visit left subtree, then root, then right subtree.
def inorder(root, result=None):
if result is None:
result = []
if root:
inorder(root.left, result)
result.append(root.data)
inorder(root.right, result)
return result
ā± O(n)
2ļøā£2ļøā£6ļøā£ Perform a Level Order Traversal (BFS) of a Binary Tree
š Use a queue to visit nodes level by level.
from collections import deque
def level_order(root):
result = []
queue = deque([root])
while queue:
node = queue.popleft()
if node:
result.append(node.data)
queue.append(node.left)
queue.append(node.right)
return result
ā± O(n)
2ļøā£2ļøā£7ļøā£ Check if a Binary Tree is a Valid BST
š Recursively verify each node falls within a valid min/max range.
def is_valid_bst(root, low=float('-inf'), high=float('inf')):
if not root:
return True
if not (low < root.data < high):
return False
return (is_valid_bst(root.left, low, root.data) and
is_valid_bst(root.right, root.data, high))
ā± O(n)
2ļøā£2ļøā£8ļøā£ Find the Lowest Common Ancestor in a BST
š Traverse down; split point where paths diverge is the LCA.
def lowest_common_ancestor(root, p, q):
while root:
if p < root.data and q < root.data:
root = root.left
elif p > root.data and q > root.data:
root = root.right
else:
return root.data
ā± O(h)
2ļøā£2ļøā£9ļøā£ Check if Two Binary Trees are Identical
š Compare values and recursively check both subtrees.
def is_identical(t1, t2):
if not t1 and not t2:
return True
if not t1 or not t2:
return False
return (t1.data == t2.data and
is_identical(t1.left, t2.left) and
is_identical(t1.right, t2.right))
ā± O(n)
2ļøā£3ļøā£0ļøā£ Find the Diameter of a Binary Tree
š The longest path between any two nodes ā may or may not pass through root.
def diameter(root):
result = [0]
def depth(node):
if not node:
return 0
left = depth(node.left)
right = depth(node.right)
result[0] = max(result[0], left + right)
return 1 + max(left, right)
depth(root)
return result[0]
ā± O(n)
š¬ Save this for your next interview prep! Should Part 7 cover Sorting Algorithms, Stacks & Queues, or Graphs? š
#coding #interview #python #programming #softwareengineer #dsa
ā¤1
š Coding Interview Questions with Answers (Part 7)
2ļøā£3ļøā£1ļøā£ Implement Bubble Sort
š Repeatedly compare adjacent elements and swap them if they are in the wrong order.
ⱠO(n²)
2ļøā£3ļøā£2ļøā£ Implement Selection Sort
š Find the smallest element and place it at the correct position.
ⱠO(n²)
2ļøā£3ļøā£3ļøā£ Implement Insertion Sort
š Build the sorted array one element at a time.
ⱠO(n²)
2ļøā£3ļøā£4ļøā£ Implement Merge Sort
š Divide the array into smaller parts, sort them, and merge them.
ā± O(n log n)
2ļøā£3ļøā£5ļøā£ Implement Quick Sort
š Select a pivot and partition the array around it.
ⱠAverage O(n log n) | Worst O(n²)
2ļøā£3ļøā£6ļøā£ Implement a Stack Using a List
š Use the end of the list for efficient push and pop operations.
ā± O(1) for push/pop
2ļøā£3ļøā£7ļøā£ Implement a Queue Using deque
š Add elements from the rear and remove them from the front.
ā± O(1) for enqueue/dequeue
š¬ Save this for your next interview prep!
š„ Should Part 8 cover Graphs, Dynamic Programming, or Recursion & Backtracking? š
#coding #interview #python #programming #softwareengineer #dsa
2ļøā£3ļøā£1ļøā£ Implement Bubble Sort
š Repeatedly compare adjacent elements and swap them if they are in the wrong order.
def bubble_sort(arr):
n = len(arr)
for i in range(n):
for j in range(0, n - i - 1):
if arr[j] > arr[j + 1]:
arr[j], arr[j + 1] = arr[j + 1], arr[j]
return arr
ⱠO(n²)
2ļøā£3ļøā£2ļøā£ Implement Selection Sort
š Find the smallest element and place it at the correct position.
def selection_sort(arr):
n = len(arr)
for i in range(n):
min_index = i
for j in range(i + 1, n):
if arr[j] < arr[min_index]:
min_index = j
arr[i], arr[min_index] = arr[min_index], arr[i]
return arr
ⱠO(n²)
2ļøā£3ļøā£3ļøā£ Implement Insertion Sort
š Build the sorted array one element at a time.
def insertion_sort(arr):
for i in range(1, len(arr)):
key = arr[i]
j = i - 1
while j >= 0 and arr[j] > key:
arr[j + 1] = arr[j]
j -= 1
arr[j + 1] = key
return arr
ⱠO(n²)
2ļøā£3ļøā£4ļøā£ Implement Merge Sort
š Divide the array into smaller parts, sort them, and merge them.
def merge_sort(arr):
if len(arr) <= 1:
return arr
mid = len(arr) // 2
left = merge_sort(arr[:mid])
right = merge_sort(arr[mid:])
result = []
i = j = 0
while i < len(left) and j < len(right):
if left[i] < right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
result.extend(left[i:])
result.extend(right[j:])
return result
ā± O(n log n)
2ļøā£3ļøā£5ļøā£ Implement Quick Sort
š Select a pivot and partition the array around it.
def quick_sort(arr):
if len(arr) <= 1:
return arr
pivot = arr[-1]
left = [x for x in arr[:-1] if x <= pivot]
right = [x for x in arr[:-1] if x > pivot]
return quick_sort(left) + [pivot] + quick_sort(right)
ⱠAverage O(n log n) | Worst O(n²)
2ļøā£3ļøā£6ļøā£ Implement a Stack Using a List
š Use the end of the list for efficient push and pop operations.
class Stack:
def __init__(self):
self.items = []
def push(self, item):
self.items.append(item)
def pop(self):
if self.items:
return self.items.pop()
return None
def peek(self):
return self.items[-1] if self.items else None
ā± O(1) for push/pop
2ļøā£3ļøā£7ļøā£ Implement a Queue Using deque
š Add elements from the rear and remove them from the front.
from collections import deque
class Queue:
def __init__(self):
self.items = deque()
def enqueue(self, item):
self.items.append(item)
def dequeue(self):
if self.items:
return self.items.popleft()
return None
ā± O(1) for enqueue/dequeue
š¬ Save this for your next interview prep!
š„ Should Part 8 cover Graphs, Dynamic Programming, or Recursion & Backtracking? š
#coding #interview #python #programming #softwareengineer #dsa
š¤ AI Interview Questions with Answers (Part 1)
1ļøā£ What is Artificial Intelligence (AI)?
š Artificial Intelligence is a branch of computer science that enables machines to learn, reason, make decisions, and perform tasks that normally require human intelligence.
Examples include:
⢠Chatbots š¤
⢠Voice Assistants šļø
⢠Recommendation Systems šÆ
⢠Self-Driving Cars š
⢠Image Recognition šø
š” Interview Tip: AI focuses on making machines capable of performing intelligent tasks.
---
2ļøā£ What are the Main Types of AI?
š AI is commonly classified based on its capabilities into three types:
š¹ Artificial Narrow Intelligence (ANI)
Designed to perform a specific task, such as face recognition or recommendation systems.
š¹ Artificial General Intelligence (AGI)
A theoretical form of AI that would perform a wide range of intellectual tasks at a human-like level.
š¹ Artificial Super Intelligence (ASI)
A hypothetical AI that would surpass human intelligence across virtually all domains.
š” Most AI systems available today are Narrow AI.
---
3ļøā£ What is Machine Learning?
š Machine Learning (ML) is a subset of AI that allows computers to learn patterns from data and make predictions or decisions without being explicitly programmed for every case.
Example:
A spam filter learns from previous emails to identify whether a new email is spam.
š” AI ā Machine Learning ā Deep Learning
---
4ļøā£ What is Deep Learning?
š Deep Learning is a subset of Machine Learning that uses multi-layer neural networks to learn complex patterns from large amounts of data.
Applications include:
⢠Image Recognition šø
⢠Speech Recognition š¤
⢠Natural Language Processing š¬
⢠Generative AI š¤
---
5ļøā£ What is a Neural Network?
š A Neural Network is a machine learning model inspired by the structure of the human brain.
It consists of:
š¹ Input Layer
š¹ Hidden Layers
š¹ Output Layer
Neural networks learn by adjusting weights and biases during training.
---
6ļøā£ What is Generative AI?
š Generative AI is a type of AI that can create new content based on patterns learned from training data.
It can generate:
š Text
š¼ļø Images
šµ Music
š» Code
š¬ Video
Examples include AI systems used for chat, image generation, and code generation.
---
7ļøā£ What is Natural Language Processing (NLP)?
š NLP is a field of AI that enables computers to understand, process, and generate human language.
Examples:
⢠Chatbots
⢠Machine Translation
⢠Sentiment Analysis
⢠Speech-to-Text
⢠Text Summarization
---
8ļøā£ What is Computer Vision?
š Computer Vision enables computers to interpret and understand visual information from images and videos.
Applications include:
šø Face Recognition
š Autonomous Vehicles
š„ Medical Image Analysis
š Object Detection
---
9ļøā£ What is an AI Model?
š An AI model is a mathematical or computational system that has learned patterns from data and can use those patterns to make predictions, classifications, or generate outputs.
Example:
Input ā AI Model ā Output
Image ā Image Classification Model ā "Cat" š±
---
š What is Training in AI?
š Training is the process of teaching an AI model by providing data and adjusting its internal parameters so that it can produce better results.
Typical process:
Data ā Training ā Model ā Evaluation ā Prediction
š” Better-quality data and appropriate training generally lead to better model performance.
---
š¬ Save this for your AI interview preparation!
š„ Should Part 2 cover Supervised Learning, Unsupervised Learning, Reinforcement Learning, Overfitting, Underfitting, and Model Evaluation? š
#AI #ArtificialIntelligence #MachineLearning #DeepLearning #AIInterview #InterviewQuestions #Python #DataScience #GenerativeAI
1ļøā£ What is Artificial Intelligence (AI)?
š Artificial Intelligence is a branch of computer science that enables machines to learn, reason, make decisions, and perform tasks that normally require human intelligence.
Examples include:
⢠Chatbots š¤
⢠Voice Assistants šļø
⢠Recommendation Systems šÆ
⢠Self-Driving Cars š
⢠Image Recognition šø
š” Interview Tip: AI focuses on making machines capable of performing intelligent tasks.
---
2ļøā£ What are the Main Types of AI?
š AI is commonly classified based on its capabilities into three types:
š¹ Artificial Narrow Intelligence (ANI)
Designed to perform a specific task, such as face recognition or recommendation systems.
š¹ Artificial General Intelligence (AGI)
A theoretical form of AI that would perform a wide range of intellectual tasks at a human-like level.
š¹ Artificial Super Intelligence (ASI)
A hypothetical AI that would surpass human intelligence across virtually all domains.
š” Most AI systems available today are Narrow AI.
---
3ļøā£ What is Machine Learning?
š Machine Learning (ML) is a subset of AI that allows computers to learn patterns from data and make predictions or decisions without being explicitly programmed for every case.
Example:
A spam filter learns from previous emails to identify whether a new email is spam.
š” AI ā Machine Learning ā Deep Learning
---
4ļøā£ What is Deep Learning?
š Deep Learning is a subset of Machine Learning that uses multi-layer neural networks to learn complex patterns from large amounts of data.
Applications include:
⢠Image Recognition šø
⢠Speech Recognition š¤
⢠Natural Language Processing š¬
⢠Generative AI š¤
---
5ļøā£ What is a Neural Network?
š A Neural Network is a machine learning model inspired by the structure of the human brain.
It consists of:
š¹ Input Layer
š¹ Hidden Layers
š¹ Output Layer
Neural networks learn by adjusting weights and biases during training.
---
6ļøā£ What is Generative AI?
š Generative AI is a type of AI that can create new content based on patterns learned from training data.
It can generate:
š Text
š¼ļø Images
šµ Music
š» Code
š¬ Video
Examples include AI systems used for chat, image generation, and code generation.
---
7ļøā£ What is Natural Language Processing (NLP)?
š NLP is a field of AI that enables computers to understand, process, and generate human language.
Examples:
⢠Chatbots
⢠Machine Translation
⢠Sentiment Analysis
⢠Speech-to-Text
⢠Text Summarization
---
8ļøā£ What is Computer Vision?
š Computer Vision enables computers to interpret and understand visual information from images and videos.
Applications include:
šø Face Recognition
š Autonomous Vehicles
š„ Medical Image Analysis
š Object Detection
---
9ļøā£ What is an AI Model?
š An AI model is a mathematical or computational system that has learned patterns from data and can use those patterns to make predictions, classifications, or generate outputs.
Example:
Input ā AI Model ā Output
Image ā Image Classification Model ā "Cat" š±
---
š What is Training in AI?
š Training is the process of teaching an AI model by providing data and adjusting its internal parameters so that it can produce better results.
Typical process:
Data ā Training ā Model ā Evaluation ā Prediction
š” Better-quality data and appropriate training generally lead to better model performance.
---
š¬ Save this for your AI interview preparation!
š„ Should Part 2 cover Supervised Learning, Unsupervised Learning, Reinforcement Learning, Overfitting, Underfitting, and Model Evaluation? š
#AI #ArtificialIntelligence #MachineLearning #DeepLearning #AIInterview #InterviewQuestions #Python #DataScience #GenerativeAI