https://leetcode.com/problems/count-good-numbers/description/


Count (0,2,4,6,8)(2,3,5,7) generated strings of length n #medium #math

https://leetcode.com/problems/count-good-triplets/description


Triplets with diff less than a,b,c #easy

https://leetcode.com/problems/count-good-triplets-in-an-array/description/


Triplets in same order in both (0..n)-arrays #hard #bit

https://leetcode.com/problems/count-the-number-of-good-subarrays/description/

Subarrays with at least k equal pairs #medium #sliding_window #math

Pairs a[i] == b[j], i * j % k == 0 #easy


https://leetcode.com/problems/count-equal-and-divisible-pairs-in-an-array/description/

https://leetcode.com/problems/count-and-say/description/


nth run-length encoded string #medium

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

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

https://leetcode.com/problems/rabbits-in-forest/description


Count total rabbits from other numbers #medium #math #brainteaser

https://leetcode.com/problems/count-the-hidden-sequences/description/


Possible arrays from diff array and lo..hi #medium

https://leetcode.com/problems/count-the-number-of-ideal-arrays/description/


Arrays a[i] % a[i - 1] == 0, i..n, a[i]..max #hard #combinatorics

https://leetcode.com/problems/count-largest-group/description/


Count of max groups by digits sum 1..n #easy

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


Subarrays having all uniqs #medium #two_pointers

https://leetcode.com/problems/count-of-interesting-subarrays/description/

Subarrays, count a[i]%m=k is c%m=k #medium #hash_map

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


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

3-subarrays 2a + 2c == b #easy


https://leetcode.com/problems/count-subarrays-of-length-three-with-a-condition/description/

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/find-numbers-with-even-number-of-digits/description/


Even length numbers #easy

Tasks can be done by workers with pills #hard #binary_search


https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign/description

Dominoes simulation #medium


https://leetcode.com/problems/push-dominoes/description/

https://leetcode.com/problems/minimum-domino-rotations-for-equal-row/description/


Min swaps to make a top or bottom row #medium