README.md

LeetCode Topics

String

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters	Medium
0020-valid-parentheses	Easy
0049-group-anagrams	Medium
0079-word-search	Medium
0179-largest-number	Medium
0383-ransom-note	Easy
0389-find-the-difference	Easy
0539-minimum-time-difference	Medium
0556-next-greater-element-iii	Medium
0657-robot-return-to-origin	Easy
0796-rotate-string	Easy
0921-minimum-add-to-make-parentheses-valid	Medium
1021-remove-outermost-parentheses	Easy
1209-remove-all-adjacent-duplicates-in-string-ii	Medium
1370-increasing-decreasing-string	Easy
1544-make-the-string-great	Easy
1662-check-if-two-string-arrays-are-equivalent	Easy
1974-minimum-time-to-type-word-using-special-typewriter	Easy

Stack

Problem Name	Difficulty
0020-valid-parentheses	Easy
0150-evaluate-reverse-polish-notation	Medium
0225-implement-stack-using-queues	Easy
0232-implement-queue-using-stacks	Easy
0496-next-greater-element-i	Easy
0735-asteroid-collision	Medium
0739-daily-temperatures	Medium
0921-minimum-add-to-make-parentheses-valid	Medium
1021-remove-outermost-parentheses	Easy
1209-remove-all-adjacent-duplicates-in-string-ii	Medium
1544-make-the-string-great	Easy

Array

Problem Name	Difficulty
0026-remove-duplicates-from-sorted-array	Easy
0034-find-first-and-last-position-of-element-in-sorted-array	Medium
0049-group-anagrams	Medium
0053-maximum-subarray	Medium
0075-sort-colors	Medium
0079-word-search	Medium
0088-merge-sorted-array	Easy
0150-evaluate-reverse-polish-notation	Medium
0153-find-minimum-in-rotated-sorted-array	Medium
0169-majority-element	Easy
0179-largest-number	Medium
0200-number-of-islands	Medium
0209-minimum-size-subarray-sum	Medium
0217-contains-duplicate	Easy
0268-missing-number	Easy
0414-third-maximum-number	Easy
0463-island-perimeter	Easy
0495-teemo-attacking	Easy
0496-next-greater-element-i	Easy
0539-minimum-time-difference	Medium
0542-01-matrix	Medium
0561-array-partition	Easy
0622-design-circular-queue	Medium
0643-maximum-average-subarray-i	Easy
0690-employee-importance	Medium
0704-binary-search	Easy
0733-flood-fill	Easy
0735-asteroid-collision	Medium
0739-daily-temperatures	Medium
0773-sliding-puzzle	Hard
0875-koko-eating-bananas	Medium
0934-shortest-bridge	Medium
0977-squares-of-a-sorted-array	Easy
0994-rotting-oranges	Medium
1304-find-n-unique-integers-sum-up-to-zero	Easy
1346-check-if-n-and-its-double-exist	Easy
1388-pizza-with-3n-slices	Hard
1431-kids-with-the-greatest-number-of-candies	Easy
1662-check-if-two-string-arrays-are-equivalent	Easy
1926-nearest-exit-from-entrance-in-maze	Medium

Two Pointers

Problem Name	Difficulty
0019-remove-nth-node-from-end-of-list	Medium
0026-remove-duplicates-from-sorted-array	Easy
0075-sort-colors	Medium
0086-partition-list	Medium
0088-merge-sorted-array	Easy
0142-linked-list-cycle-ii	Medium
0160-intersection-of-two-linked-lists	Easy
0556-next-greater-element-iii	Medium
0876-middle-of-the-linked-list	Easy
0977-squares-of-a-sorted-array	Easy
1237-find-positive-integer-solution-for-a-given-equation	Medium
1346-check-if-n-and-its-double-exist	Easy

Sorting

Problem Name	Difficulty
0049-group-anagrams	Medium
0075-sort-colors	Medium
0088-merge-sorted-array	Easy
0169-majority-element	Easy
0179-largest-number	Medium
0217-contains-duplicate	Easy
0268-missing-number	Easy
0389-find-the-difference	Easy
0414-third-maximum-number	Easy
0539-minimum-time-difference	Medium
0561-array-partition	Easy
0977-squares-of-a-sorted-array	Easy
1346-check-if-n-and-its-double-exist	Easy

Hash Table

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters	Medium
0049-group-anagrams	Medium
0142-linked-list-cycle-ii	Medium
0160-intersection-of-two-linked-lists	Easy
0169-majority-element	Easy
0217-contains-duplicate	Easy
0268-missing-number	Easy
0383-ransom-note	Easy
0389-find-the-difference	Easy
0496-next-greater-element-i	Easy
0690-employee-importance	Medium
1346-check-if-n-and-its-double-exist	Easy
1370-increasing-decreasing-string	Easy

Counting

Problem Name	Difficulty
0169-majority-element	Easy
0383-ransom-note	Easy
1370-increasing-decreasing-string	Easy

Bit Manipulation

Problem Name	Difficulty
0268-missing-number	Easy
0389-find-the-difference	Easy

Sliding Window

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters	Medium
0209-minimum-size-subarray-sum	Medium
0643-maximum-average-subarray-i	Easy

Simulation

Problem Name	Difficulty
0495-teemo-attacking	Easy
0657-robot-return-to-origin	Easy
0735-asteroid-collision	Medium

Linked List

Problem Name	Difficulty
0019-remove-nth-node-from-end-of-list	Medium
0024-swap-nodes-in-pairs	Medium
0083-remove-duplicates-from-sorted-list	Easy
0086-partition-list	Medium
0109-convert-sorted-list-to-binary-search-tree	Medium
0142-linked-list-cycle-ii	Medium
0160-intersection-of-two-linked-lists	Easy
0203-remove-linked-list-elements	Easy
0206-reverse-linked-list	Easy
0237-delete-node-in-a-linked-list	Medium
0622-design-circular-queue	Medium
0876-middle-of-the-linked-list	Easy

Recursion

Problem Name	Difficulty
0024-swap-nodes-in-pairs	Medium
0203-remove-linked-list-elements	Easy
0206-reverse-linked-list	Easy

Design

Problem Name	Difficulty
0225-implement-stack-using-queues	Easy
0232-implement-queue-using-stacks	Easy
0622-design-circular-queue	Medium

Queue

Problem Name	Difficulty
0225-implement-stack-using-queues	Easy
0232-implement-queue-using-stacks	Easy
0622-design-circular-queue	Medium

Math

Problem Name	Difficulty
0069-sqrtx	Easy
0150-evaluate-reverse-polish-notation	Medium
0268-missing-number	Easy
0367-valid-perfect-square	Easy
0539-minimum-time-difference	Medium
0556-next-greater-element-iii	Medium
1237-find-positive-integer-solution-for-a-given-equation	Medium
1304-find-n-unique-integers-sum-up-to-zero	Easy

Binary Search

Problem Name	Difficulty
0034-find-first-and-last-position-of-element-in-sorted-array	Medium
0069-sqrtx	Easy
0153-find-minimum-in-rotated-sorted-array	Medium
0209-minimum-size-subarray-sum	Medium
0268-missing-number	Easy
0367-valid-perfect-square	Easy
0704-binary-search	Easy
0875-koko-eating-bananas	Medium
1237-find-positive-integer-solution-for-a-given-equation	Medium
1346-check-if-n-and-its-double-exist	Easy

Greedy

Problem Name	Difficulty
0179-largest-number	Medium
0561-array-partition	Easy
0921-minimum-add-to-make-parentheses-valid	Medium
1388-pizza-with-3n-slices	Hard
1974-minimum-time-to-type-word-using-special-typewriter	Easy

Counting Sort

Problem Name	Difficulty
0561-array-partition	Easy

Divide and Conquer

Problem Name	Difficulty
0053-maximum-subarray	Medium
0109-convert-sorted-list-to-binary-search-tree	Medium
0169-majority-element	Easy

Tree

Problem Name	Difficulty
0104-maximum-depth-of-binary-tree	Easy
0109-convert-sorted-list-to-binary-search-tree	Medium
0111-minimum-depth-of-binary-tree	Easy
0226-invert-binary-tree	Easy
0543-diameter-of-binary-tree	Easy
0559-maximum-depth-of-n-ary-tree	Easy
0690-employee-importance	Medium
0872-leaf-similar-trees	Easy

Binary Search Tree

Problem Name	Difficulty
0109-convert-sorted-list-to-binary-search-tree	Medium

Binary Tree

Problem Name	Difficulty
0104-maximum-depth-of-binary-tree	Easy
0109-convert-sorted-list-to-binary-search-tree	Medium
0111-minimum-depth-of-binary-tree	Easy
0226-invert-binary-tree	Easy
0543-diameter-of-binary-tree	Easy
0872-leaf-similar-trees	Easy

Monotonic Stack

Problem Name	Difficulty
0496-next-greater-element-i	Easy
0739-daily-temperatures	Medium

Interactive

Problem Name	Difficulty
1237-find-positive-integer-solution-for-a-given-equation	Medium

Dynamic Programming

Problem Name	Difficulty
0053-maximum-subarray	Medium
0542-01-matrix	Medium
0773-sliding-puzzle	Hard
1388-pizza-with-3n-slices	Hard

Heap (Priority Queue)

Problem Name	Difficulty
1388-pizza-with-3n-slices	Hard

Depth-First Search

Problem Name	Difficulty
0079-word-search	Medium
0104-maximum-depth-of-binary-tree	Easy
0111-minimum-depth-of-binary-tree	Easy
0200-number-of-islands	Medium
0226-invert-binary-tree	Easy
0463-island-perimeter	Easy
0543-diameter-of-binary-tree	Easy
0547-number-of-provinces	Medium
0559-maximum-depth-of-n-ary-tree	Easy
0690-employee-importance	Medium
0733-flood-fill	Easy
0785-is-graph-bipartite	Medium
0841-keys-and-rooms	Medium
0872-leaf-similar-trees	Easy
0934-shortest-bridge	Medium

Breadth-First Search

Problem Name	Difficulty
0104-maximum-depth-of-binary-tree	Easy
0111-minimum-depth-of-binary-tree	Easy
0200-number-of-islands	Medium
0226-invert-binary-tree	Easy
0463-island-perimeter	Easy
0542-01-matrix	Medium
0547-number-of-provinces	Medium
0559-maximum-depth-of-n-ary-tree	Easy
0690-employee-importance	Medium
0733-flood-fill	Easy
0773-sliding-puzzle	Hard
0785-is-graph-bipartite	Medium
0841-keys-and-rooms	Medium
0934-shortest-bridge	Medium
0994-rotting-oranges	Medium
1926-nearest-exit-from-entrance-in-maze	Medium

Matrix

Problem Name	Difficulty
0079-word-search	Medium
0200-number-of-islands	Medium
0463-island-perimeter	Easy
0542-01-matrix	Medium
0733-flood-fill	Easy
0773-sliding-puzzle	Hard
0934-shortest-bridge	Medium
0994-rotting-oranges	Medium
1926-nearest-exit-from-entrance-in-maze	Medium

Union-Find

Problem Name	Difficulty
0200-number-of-islands	Medium
0547-number-of-provinces	Medium
0785-is-graph-bipartite	Medium

Graph Theory

Problem Name	Difficulty
0547-number-of-provinces	Medium
0785-is-graph-bipartite	Medium
0841-keys-and-rooms	Medium

Backtracking

Problem Name	Difficulty
0079-word-search	Medium
0773-sliding-puzzle	Hard

Memoization

Problem Name	Difficulty
0773-sliding-puzzle	Hard

Prefix Sum

Problem Name	Difficulty
0209-minimum-size-subarray-sum	Medium

String Matching

Problem Name	Difficulty
0796-rotate-string	Easy