Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

An input string is valid if:

Open brackets must be closed by the same type of brackets.
Open brackets must be closed in the correct order.
Every close bracket has a corresponding open bracket of the same type.complete it today by Eod

Example 1:

Input: s = "()"
Output: true
Example 2:

Input: s = "()[]{}"
Output: true
Example 3:

Input: s = "(]"
Output: false


Constraints:

1 <= s.length <= 104
s consists of parentheses only '()[]{}'.

3 possible solutions as per me

You are given the heads of two sorted linked lists list1 and list2.

Merge the two lists in a one sorted list. The list should be made by splicing together the nodes of the first two lists.

Return the head of the merged linked list.



Example 1:


Input: list1 = [1,2,4], list2 = [1,3,4]
Output: [1,1,2,3,4,4]
Example 2:

Input: list1 = [], list2 = []
Output: []
Example 3:

Input: list1 = [], list2 = [0]
Output: [0]


Constraints:

The number of nodes in both lists is in the range [0, 50].
-100 <= Node.val <= 100
Both list1 and list2 are sorted in non-decreasing order.

/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
ListNode head = new ListNode(0);

if(list1 == null && list2 == null) return null; //null checking
if(list1 == null) return list2;
if(list2 == null) return list1;

if(list1.val > list2.val) { //comparing and merging
head = list2;
list2 = list2.next;
}
else {
head = list1;
list1 = list1.next;
}

head.next = mergeTwoLists(list1, list2);
return head;
}
}

Good question n lot much tricky

Marked as easy 😂 but it's headache question

The n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other.

Given an integer n, return all distinct solutions to the n-queens puzzle. You may return the answer in any order.

Each solution contains a distinct board configuration of the n-queens' placement, where 'Q' and '.' both indicate a queen and an empty space, respectively.



Example 1:


Input: n = 4
Output: [[".Q..","...Q","Q...","..Q."],["..Q.","Q...","...Q",".Q.."]]
Explanation: There exist two distinct solutions to the 4-queens puzzle as shown above
Example 2:

Input: n = 1
Output: [["Q"]]


Constraints:

1 <= n <= 9

class Solution {
public List<List<String>> solveNQueens(int n) {

}
}

int a= 10;
int b = 20;
gpay G = (r,s)->{r*s};
G.amount(a,b);

gpay G : test::amountgpay;

test t = new test();
PhonePay P : t::amountPhonepay

liste.stream().filter(a->a.basicSal > 45000).collect(Collectors.toList()).forEach(System.out::println);

Introduced in Java 8, the Stream API is used to process collections of objects. A stream is a sequence of objects that supports various methods which can be pipelined to produce the desired result. A stream is not a data structure instead it takes input from the Collections, Arrays or I/O channels.

Reference code

public class test {
public void Wa() {
System.out.println("i am from common bank");
}

public static void amount(int x, int y) {
System.out.println("Sender is "+ x +" and receiver is " +y);
}


public static void main(String... args) {



Withdraws a = new Withdraws() {
//Anonymous methods/ class we can use everywhere
@Override
public void withdrawAmount() {
// TODO Auto-generated method stub
System.out.println("i am from axisbank u can withdraw 40000.");
}};
//Lambda expression only for functional interfaces (SAM:- single abstract methods)
Withdraws h = ()-> {System.out.println("i am from hdfcBank u can withdraw 20,000");};//new hdfcBank();
Withdraws i = new iciciBank();//normal way
test t = new test();
Withdraws c = t::Wa;// method reference with instance method
int aa = 100;
// phonePay p = (v)->{System.out.println("Account bal is " + (v*100));};
// p.amount(aa);

// gpay g = (x, y) -> {System.out.println("Sender is "+ x +" and receiver is " +y);};
// g.amount(420, 440);

gpay g = test::amount;
g.amount(420, 440);
c.withdrawAmount();
a.withdrawAmount();
i.withdrawAmount();
h.withdrawAmount();
//default methods :- if we are implementing n number of
}
}

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.function.Consumer;
import java.util.stream.*;
public class EdM1 extends EdM{

//private static final Object e = null;

public EdM1(int empNo, String empName, String gender, int basicSal, String city, String deptName) {
super(empNo, empName, gender, basicSal, city, deptName);
}

@SuppressWarnings("unchecked")
public static void main(String[] args) {
List <EdM1> liste= new ArrayList<EdM1>();
liste.add(new EdM1(1001,"Kannababu","m",40000,"Hyderabad","EIE"));
liste.add(new EdM1(1002,"Srinivas","m",42000,"Chennai","CSE"));
liste.add(new EdM1(1003,"Yakub","m",45000,"Banglore","CSE"));
liste.add(new EdM1(1004,"Venktesh","m",55000,"Hyderabad","CSE"));
liste.add(new EdM1(1005,"Samantha","f",65000,"Chennai","ECE"));
liste.add(new EdM1(1006,"Anushka","f",43000,"Banglore","EIE"));
liste.add(new EdM1(1007,"Shekhar","m",23000,"Banglore","EIE"));
//Q1.)
float sum=0;
float da;
float hra;float tsal;
for(EdM1 e:list) {
// System.out.println(e.empNo+","+e.empName+","+e.gender+","+e.basicSal+","+e.city+","+e.deptName);
System.out.println(e.toString());

// //Q2.)
// if(e.basicSal>45000)
// System.out.println(e.toString());
// //Q3.)
// if (e.city.equalsIgnoreCase("Hyderabad"))
// System.out.println(e.toString());
// //Q4.)
// System.out.println(list.size());
// //Q5.)
// if(e.deptName.equalsIgnoreCase("CSE"))
// System.out.println(e.toString());
// //Q6.)
// if(e.basicSal>45000 && e.basicSal<60000)
// System.out.println(e.toString());
// //Q7.)
// if(e.gender.equalsIgnoreCase("m") || e.gender.equalsIgnoreCase("f"))
// System.out.println(e.toString());
// //Q8.)
// if (e.city.equalsIgnoreCase("Hyderabad")&& e.basicSal>40000)
// System.out.println(e.toString());
// //Q9.)
// if (e.city.equalsIgnoreCase("Banglore"))

// for(int i = 0;i<list.size();i++)
// sum+= list.get(i);
//
// System.out.println(sum);
// sum = sum+ e.basicSal;
// }
// System.out.println(sum);
// System.out.println(e.toString());
// //Q10.)
// if(e.deptName.equalsIgnoreCase("ECE"))
// System.out.println(e.toString());
// //Q11.)
// da=(float) (0.20+basicSal);
// hra=(float) (0.40+basicSal);
// tsal = da + hra + basicSal;
// System.out.println(e.toString()+tsal);
//Q12.)
// if(e.empName.equalsIgnoreCase("Samantha"))
// System.out.println(e.basicSal);
// }
// Comparator com = (Object o1, Object o2)-> {
// EdM e1 = (EdM)o1;
// EdM e2 = (EdM)o2;
// return e2.empName.compareTo(e1.empName);
// };
// Collections.sort(liste, com);
// for(EdM1 a : liste) {
// System.out.println(a.toString());
// }
//Consumer c = (e) -> {System.out.println(e);};
// Consumer c = System.out::println;
// liste.forEach(c);
// Stream s = liste.stream().filter(e-> e.basicSal > 45000);
// s.forEach(System.out::println);

Top Java Interview Questions and Answers (2022) - InterviewBit
https://www.interviewbit.com/java-interview-questions/amp/

Join here for messaging