Leetcode-Solutions

LeetCode Topics

Array

Problem Name	Difficulty
0004-median-of-two-sorted-arrays	Hard
0066-plus-one	Easy
0106-construct-binary-tree-from-inorder-and-postorder-traversal	Medium
0204-count-primes	Medium
0212-word-search-ii	Hard
0486-predict-the-winner	Medium
0628-maximum-product-of-three-numbers	Easy
0724-find-pivot-index	Easy
0812-largest-triangle-area	Easy
0877-stone-game	Medium
0883-projection-area-of-3d-shapes	Easy
1140-stone-game-ii	Medium
1260-shift-2d-grid	Easy
1288-remove-covered-intervals	Medium
1331-rank-transform-of-an-array	Easy
1406-stone-game-iii	Hard
1464-maximum-product-of-two-elements-in-an-array	Easy
1872-stone-game-viii	Hard
1979-find-greatest-common-divisor-of-array	Easy
2029-stone-game-ix	Medium
2091-removing-minimum-and-maximum-from-array	Medium
2948-make-lexicographically-smallest-array-by-swapping-elements	Medium
2958-length-of-longest-subarray-with-at-most-k-frequency	Medium
2996-smallest-missing-integer-greater-than-sequential-prefix-sum	Easy
3471-find-the-largest-almost-missing-integer	Easy
3513-number-of-unique-xor-triplets-i	Medium
3514-number-of-unique-xor-triplets-ii	Medium
3702-longest-subsequence-with-non-zero-bitwise-xor	Medium
3718-smallest-missing-multiple-of-k	Easy
3731-find-missing-elements	Easy
3867-sum-of-gcd-of-formed-pairs	Medium

Sorting

Problem Name	Difficulty
0295-find-median-from-data-stream	Hard
0628-maximum-product-of-three-numbers	Easy
1288-remove-covered-intervals	Medium
1331-rank-transform-of-an-array	Easy
1464-maximum-product-of-two-elements-in-an-array	Easy
2948-make-lexicographically-smallest-array-by-swapping-elements	Medium
2996-smallest-missing-integer-greater-than-sequential-prefix-sum	Easy
3016-minimum-number-of-pushes-to-type-word-ii	Medium
3517-smallest-palindromic-rearrangement-i	Medium
3536-maximum-product-of-two-digits	Easy
3731-find-missing-elements	Easy
3867-sum-of-gcd-of-formed-pairs	Medium

Math

Problem Name	Difficulty
0002-add-two-numbers	Medium
0060-permutation-sequence	Hard
0066-plus-one	Easy
0070-climbing-stairs	Easy
0172-factorial-trailing-zeroes	Medium
0204-count-primes	Medium
0486-predict-the-winner	Medium
0628-maximum-product-of-three-numbers	Easy
0812-largest-triangle-area	Easy
0858-mirror-reflection	Medium
0877-stone-game	Medium
0883-projection-area-of-3d-shapes	Easy
1140-stone-game-ii	Medium
1406-stone-game-iii	Hard
1510-stone-game-iv	Hard
1866-number-of-ways-to-rearrange-sticks-with-k-sticks-visible	Hard
1872-stone-game-viii	Hard
1927-sum-game	Medium
1979-find-greatest-common-divisor-of-array	Easy
2029-stone-game-ix	Medium
2523-closest-prime-numbers-in-range	Medium
3014-minimum-number-of-pushes-to-type-word-i	Easy
3345-smallest-divisible-digit-product-i	Easy
3348-smallest-divisible-digit-product-ii	Hard
3513-number-of-unique-xor-triplets-i	Medium
3514-number-of-unique-xor-triplets-ii	Medium
3518-smallest-palindromic-rearrangement-ii	Hard
3536-maximum-product-of-two-digits	Easy
3622-check-divisibility-by-digit-sum-and-product	Easy
3658-gcd-of-odd-and-even-sums	Easy
3754-concatenate-non-zero-digits-and-multiply-by-sum-i	Easy
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii	Medium
3867-sum-of-gcd-of-formed-pairs	Medium

Dynamic Programming

Problem Name	Difficulty
0070-climbing-stairs	Easy
0486-predict-the-winner	Medium
0600-non-negative-integers-without-consecutive-ones	Hard
0877-stone-game	Medium
1140-stone-game-ii	Medium
1406-stone-game-iii	Hard
1510-stone-game-iv	Hard
1866-number-of-ways-to-rearrange-sticks-with-k-sticks-visible	Hard
1872-stone-game-viii	Hard

Combinatorics

Problem Name	Difficulty
1866-number-of-ways-to-rearrange-sticks-with-k-sticks-visible	Hard
3518-smallest-palindromic-rearrangement-ii	Hard

Backtracking

Problem Name	Difficulty
0077-combinations	Medium
0212-word-search-ii	Hard
3348-smallest-divisible-digit-product-ii	Hard

Enumeration

Problem Name	Difficulty
0204-count-primes	Medium
1291-sequential-digits	Medium
3345-smallest-divisible-digit-product-i	Easy
3499-maximize-active-section-with-trade-i	Medium
3514-number-of-unique-xor-triplets-ii	Medium
3720-lexicographically-smallest-permutation-greater-than-target	Medium
3734-lexicographically-smallest-palindromic-permutation-greater-than-target	Hard

Number Theory

Problem Name	Difficulty
0204-count-primes	Medium
0858-mirror-reflection	Medium
1979-find-greatest-common-divisor-of-array	Easy
2523-closest-prime-numbers-in-range	Medium
3348-smallest-divisible-digit-product-ii	Hard
3658-gcd-of-odd-and-even-sums	Easy
3867-sum-of-gcd-of-formed-pairs	Medium

Geometry

Problem Name	Difficulty
0812-largest-triangle-area	Easy
0858-mirror-reflection	Medium
0883-projection-area-of-3d-shapes	Easy

Matrix

Problem Name	Difficulty
0212-word-search-ii	Hard
0883-projection-area-of-3d-shapes	Easy
1260-shift-2d-grid	Easy

String

Problem Name	Difficulty
0208-implement-trie-prefix-tree	Medium
0211-design-add-and-search-words-data-structure	Medium
0212-word-search-ii	Hard
1768-merge-strings-alternately	Easy
1927-sum-game	Medium
2904-shortest-and-lexicographically-smallest-beautiful-string	Medium
3014-minimum-number-of-pushes-to-type-word-i	Easy
3016-minimum-number-of-pushes-to-type-word-ii	Medium
3090-maximum-length-substring-with-two-occurrences	Easy
3348-smallest-divisible-digit-product-ii	Hard
3499-maximize-active-section-with-trade-i	Medium
3517-smallest-palindromic-rearrangement-i	Medium
3518-smallest-palindromic-rearrangement-ii	Hard
3720-lexicographically-smallest-permutation-greater-than-target	Medium
3734-lexicographically-smallest-palindromic-permutation-greater-than-target	Hard
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii	Medium

Prefix Sum

Problem Name	Difficulty
0724-find-pivot-index	Easy
1140-stone-game-ii	Medium
1872-stone-game-viii	Hard
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii	Medium

Linked List

Problem Name	Difficulty
0002-add-two-numbers	Medium
0146-lru-cache	Medium
2058-find-the-minimum-and-maximum-number-of-nodes-between-critical-points	Medium

Recursion

Problem Name	Difficulty
0002-add-two-numbers	Medium
0060-permutation-sequence	Hard
0486-predict-the-winner	Medium

Hash Table

Problem Name	Difficulty
0106-construct-binary-tree-from-inorder-and-postorder-traversal	Medium
0146-lru-cache	Medium
0208-implement-trie-prefix-tree	Medium
1331-rank-transform-of-an-array	Easy
2958-length-of-longest-subarray-with-at-most-k-frequency	Medium
2996-smallest-missing-integer-greater-than-sequential-prefix-sum	Easy
3016-minimum-number-of-pushes-to-type-word-ii	Medium
3090-maximum-length-substring-with-two-occurrences	Easy
3471-find-the-largest-almost-missing-integer	Easy
3518-smallest-palindromic-rearrangement-ii	Hard
3718-smallest-missing-multiple-of-k	Easy
3720-lexicographically-smallest-permutation-greater-than-target	Medium
3731-find-missing-elements	Easy

Two Pointers

Problem Name	Difficulty
0295-find-median-from-data-stream	Hard
1768-merge-strings-alternately	Easy
3734-lexicographically-smallest-palindromic-permutation-greater-than-target	Hard
3867-sum-of-gcd-of-formed-pairs	Medium

Simulation

Problem Name	Difficulty
1260-shift-2d-grid	Easy
3867-sum-of-gcd-of-formed-pairs	Medium

Design

Problem Name	Difficulty
0146-lru-cache	Medium
0208-implement-trie-prefix-tree	Medium
0211-design-add-and-search-words-data-structure	Medium
0295-find-median-from-data-stream	Hard

Heap (Priority Queue)

Problem Name	Difficulty
0295-find-median-from-data-stream	Hard
1464-maximum-product-of-two-elements-in-an-array	Easy

Data Stream

Problem Name	Difficulty
0295-find-median-from-data-stream	Hard

Binary Search

Problem Name	Difficulty
0004-median-of-two-sorted-arrays	Hard

Divide and Conquer

Problem Name	Difficulty
0004-median-of-two-sorted-arrays	Hard
0106-construct-binary-tree-from-inorder-and-postorder-traversal	Medium

Bit Manipulation

Problem Name	Difficulty
3513-number-of-unique-xor-triplets-i	Medium
3514-number-of-unique-xor-triplets-ii	Medium
3702-longest-subsequence-with-non-zero-bitwise-xor	Medium

Counting Sort

Problem Name	Difficulty
2029-stone-game-ix	Medium
3016-minimum-number-of-pushes-to-type-word-ii	Medium
3517-smallest-palindromic-rearrangement-i	Medium
3518-smallest-palindromic-rearrangement-ii	Hard
3720-lexicographically-smallest-permutation-greater-than-target	Medium

Memoization

Problem Name	Difficulty
0070-climbing-stairs	Easy

Trie

Problem Name	Difficulty
0208-implement-trie-prefix-tree	Medium
0211-design-add-and-search-words-data-structure	Medium
0212-word-search-ii	Hard

Greedy

Problem Name	Difficulty
1927-sum-game	Medium
2029-stone-game-ix	Medium
2091-removing-minimum-and-maximum-from-array	Medium
3014-minimum-number-of-pushes-to-type-word-i	Easy
3016-minimum-number-of-pushes-to-type-word-ii	Medium
3348-smallest-divisible-digit-product-ii	Hard
3720-lexicographically-smallest-permutation-greater-than-target	Medium

Depth-First Search

Problem Name	Difficulty
0211-design-add-and-search-words-data-structure	Medium
3310-remove-methods-from-project	Medium

Game Theory

Problem Name	Difficulty
0486-predict-the-winner	Medium
0877-stone-game	Medium
1140-stone-game-ii	Medium
1406-stone-game-iii	Hard
1510-stone-game-iv	Hard
1872-stone-game-viii	Hard
1927-sum-game	Medium
2029-stone-game-ix	Medium

Polygons

Problem Name	Difficulty
0812-largest-triangle-area	Easy

Doubly-Linked List

Problem Name	Difficulty
0146-lru-cache	Medium

Breadth-First Search

Problem Name	Difficulty
3310-remove-methods-from-project	Medium

Graph Theory

Problem Name	Difficulty
3310-remove-methods-from-project	Medium

Primality Test

Problem Name	Difficulty
0204-count-primes	Medium

Sieve Theory

Problem Name	Difficulty
0204-count-primes	Medium

Prime Number Sieve

Problem Name	Difficulty
0204-count-primes	Medium

Tree

Problem Name	Difficulty
0106-construct-binary-tree-from-inorder-and-postorder-traversal	Medium

Binary Tree

Problem Name	Difficulty
0106-construct-binary-tree-from-inorder-and-postorder-traversal	Medium

Minimax

Problem Name	Difficulty
1140-stone-game-ii	Medium
1510-stone-game-iv	Hard
1872-stone-game-viii	Hard
2029-stone-game-ix	Medium

Zero-Sum Game

Problem Name	Difficulty
1140-stone-game-ii	Medium
1510-stone-game-iv	Hard
1872-stone-game-viii	Hard
2029-stone-game-ix	Medium

Nim Game

Problem Name	Difficulty
1510-stone-game-iv	Hard
2029-stone-game-ix	Medium

Sprague–Grundy Theorem

Problem Name	Difficulty
1510-stone-game-iv	Hard

Sliding Window

Problem Name	Difficulty
2904-shortest-and-lexicographically-smallest-beautiful-string	Medium
2958-length-of-longest-subarray-with-at-most-k-frequency	Medium
3090-maximum-length-substring-with-two-occurrences	Easy

Union-Find

Problem Name	Difficulty
2948-make-lexicographically-smallest-array-by-swapping-elements	Medium