https://leetcode.com/problems/merge-k-sorted-lists/
https://leetcode.com/problems/linked-list-cycle/
https://leetcode.com/problems/add-two-numbers/
https://leetcode.com/problems/reverse-linked-list/
https://leetcode.com/problems/binary-search/
https://leetcode.com/problems/guess-number-higher-or-lower/
https://leetcode.com/problems/search-a-2d-matrix/
https://leetcode.com/problems/search-in-rotated-sorted-array/
https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/
https://leetcode.com/problems/search-in-rotated-sorted-array-ii/
https://leetcode.com/problems/single-number/ - решить за O(1) по памяти
https://leetcode.com/problems/two-sum/
https://leetcode.com/problems/4sum/
https://leetcode.com/problems/group-anagrams/
https://leetcode.com/problems/valid-anagram/
https://leetcode.com/problems/find-all-anagrams-in-a-string/