linked lists:
- 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/
binary search:
- 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/
hash table:
- https://leetcode.com/problems/single-number/
- 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/
queue/stack:
dfs/bfs:
- https://leetcode.com/problems/number-of-islands/
- https://leetcode.com/problems/remove-invalid-parentheses/
sort:
heap/hash:
- https://leetcode.com/problems/top-k-frequent-words/
- https://leetcode.com/problems/top-k-frequent-elements/
two pointers:
- https://leetcode.com/problems/container-with-most-water/
- https://leetcode.com/problems/partition-labels/
sliding window:
- https://leetcode.com/problems/sliding-window-median/
- https://leetcode.com/problems/sliding-window-maximum/
- https://leetcode.com/problems/longest-repeating-character-replacement/
tree:
- https://leetcode.com/problems/same-tree/
- https://leetcode.com/problems/symmetric-tree/
- https://leetcode.com/problems/balanced-binary-tree/
- https://leetcode.com/problems/path-sum-ii/
greedy problems: