https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts/description/

Longest substring with even number of "aeiou" #medium #bit_manipulation #two_pointers

https://leetcode.com/problems/permutation-in-string/description/


Is s2 contains permutation of s1? #medium #two_pointers

https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balanced/description/


Min swaps to balance brackets #medium #two_pointers #stack

https://leetcode.com/problems/string-compression-iii/description/



Compress repeating chars in string #medium #two_pointers

https://leetcode.com/problems/count-the-number-of-fair-pairs/description/



Count pairs a[i] + a[j] in lower..upper #medium #binary_search #two_pointers

https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted/description/

Min subarray remove to make array sorted #medium #two_pointers

https://leetcode.com/problems/take-k-of-each-character-from-left-and-right/description/


Min take k of a,b,c from head or tail #medium #two_pointers

https://leetcode.com/problems/special-array-ii/description/

Queries is all adjucents parity differ [i..j] #medium #two_pointers

Count cycling alterating k-subarrays #medium #two_pointers


https://leetcode.com/problems/alternating-groups-ii/description

Substring with all vowels and k others #medium #two_pointers



https://leetcode.com/problems/count-of-substrings-containing-every-vowel-and-k-consonants-ii/description/

Substrings with [abc] #medium #two_pointers



https://leetcode.com/problems/number-of-substrings-containing-all-three-characters/description/

Max window of all pairs AND zero #medium #two_pointers #bit_manipulation


https://leetcode.com/problems/longest-nice-subarray/description/

https://leetcode.com/problems/count-the-number-of-fair-pairs/description/

Pairs a + b in lower..upper #medium #two_pointers

https://leetcode.com/problems/count-complete-subarrays-in-an-array/description/


Subarrays having all uniqs #medium #two_pointers

https://leetcode.com/problems/count-subarrays-with-fixed-bounds/description


Subarrays with min=minK, max=maxK #hard #two_pointers

https://leetcode.com/problems/count-subarrays-with-score-less-than-k/description/

Subarrays sum * cnt <= k #hard #two_pointers

Subarrays at least k maxes #medium #two_pointers


https://leetcode.com/problems/count-subarrays-where-max-element-appears-at-least-k-times/description

https://leetcode.com/problems/sort-colors/description


Sort 0,1,2 array #medium #two_pointers

# 29.06.2025
[1498. Number of Subsequences That Satisfy the Given Sum Condition](https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition/description/) medium


Subsequencies target in 0..min+max #medium #binary_search #two_pointers

# 30.06.2025
[594. Longest Harmonious Subsequence](https://leetcode.com/problems/longest-harmonious-subsequence/description) easy


Longest subsequence with max-min=1 #easy #counting #sort #two_pointers