Leetcode

LeetCode Topics

Array

3286-find-a-safe-walk-through-a-grid
3620-network-recovery-pathways
1301-number-of-paths-with-max-score
0300-longest-increasing-subsequence
1547-minimum-cost-to-cut-a-stick
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0188-best-time-to-buy-and-sell-stock-iv
1288-remove-covered-intervals
3532-path-existence-queries-in-a-graph-i
3534-path-existence-queries-in-a-graph-ii
0167-two-sum-ii-input-array-is-sorted
0080-remove-duplicates-from-sorted-array-ii
0026-remove-duplicates-from-sorted-array
0977-squares-of-a-sorted-array
0015-3sum
0016-3sum-closest
0018-4sum
0581-shortest-unsorted-continuous-subarray
1331-rank-transform-of-an-array
0209-minimum-size-subarray-sum
3867-sum-of-gcd-of-formed-pairs
3312-sorted-gcd-pair-queries
0904-fruit-into-baskets
1979-find-greatest-common-divisor-of-array
0287-find-the-duplicate-number
0053-maximum-subarray
0152-maximum-product-subarray
1186-maximum-subarray-sum-with-one-deletion
1749-maximum-absolute-sum-of-any-subarray
0918-maximum-sum-circular-subarray
0560-subarray-sum-equals-k
0724-find-pivot-index
0974-subarray-sums-divisible-by-k
0525-contiguous-array
0862-shortest-subarray-with-sum-at-least-k
0327-count-of-range-sum
1260-shift-2d-grid
0056-merge-intervals
0057-insert-interval
0986-interval-list-intersections
3501-maximize-active-section-with-trade-ii
3514-number-of-unique-xor-triplets-ii
0628-maximum-product-of-three-numbers
1464-maximum-product-of-two-elements-in-an-array
0486-predict-the-winner
0877-stone-game
1406-stone-game-iii
3731-find-missing-elements
1140-stone-game-ii
2958-length-of-longest-subarray-with-at-most-k-frequency
2213-longest-substring-of-one-repeating-character
2029-stone-game-ix
1563-stone-game-v
1386-cinema-seat-allocation
3069-distribute-elements-into-two-arrays-i
3116-kth-smallest-amount-with-single-denomination-combination
1872-stone-game-viii
3718-smallest-missing-multiple-of-k
2948-make-lexicographically-smallest-array-by-swapping-elements
2091-removing-minimum-and-maximum-from-array
3568-minimum-moves-to-clean-the-classroom
3875-construct-uniform-parity-array-i
3876-construct-uniform-parity-array-ii
3903-smallest-stable-index-i
3904-smallest-stable-index-ii

Breadth-First Search

3286-find-a-safe-walk-through-a-grid
2492-minimum-score-of-a-path-between-two-cities
2685-count-the-number-of-complete-components
3310-remove-methods-from-project
3568-minimum-moves-to-clean-the-classroom

Graph Theory

3286-find-a-safe-walk-through-a-grid
3620-network-recovery-pathways
2492-minimum-score-of-a-path-between-two-cities
3532-path-existence-queries-in-a-graph-i
3534-path-existence-queries-in-a-graph-ii
2685-count-the-number-of-complete-components
3310-remove-methods-from-project

Heap (Priority Queue)

3286-find-a-safe-walk-through-a-grid
3620-network-recovery-pathways
0862-shortest-subarray-with-sum-at-least-k
1464-maximum-product-of-two-elements-in-an-array

Matrix

3286-find-a-safe-walk-through-a-grid
1301-number-of-paths-with-max-score
1260-shift-2d-grid
3568-minimum-moves-to-clean-the-classroom

Shortest Path

3286-find-a-safe-walk-through-a-grid
3620-network-recovery-pathways

Binary Search

3620-network-recovery-pathways
0300-longest-increasing-subsequence
3532-path-existence-queries-in-a-graph-i
3534-path-existence-queries-in-a-graph-ii
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
3312-sorted-gcd-pair-queries
0287-find-the-duplicate-number
0862-shortest-subarray-with-sum-at-least-k
0327-count-of-range-sum
3501-maximize-active-section-with-trade-ii
3116-kth-smallest-amount-with-single-denomination-combination

Dynamic Programming

3620-network-recovery-pathways
1301-number-of-paths-with-max-score
0300-longest-increasing-subsequence
1547-minimum-cost-to-cut-a-stick
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0188-best-time-to-buy-and-sell-stock-iv
3534-path-existence-queries-in-a-graph-ii
0053-maximum-subarray
0152-maximum-product-subarray
1186-maximum-subarray-sum-with-one-deletion
1749-maximum-absolute-sum-of-any-subarray
0918-maximum-sum-circular-subarray
0486-predict-the-winner
0877-stone-game
1406-stone-game-iii
3302-find-the-lexicographically-smallest-valid-sequence
1140-stone-game-ii
1510-stone-game-iv
1563-stone-game-v
1872-stone-game-viii
0115-distinct-subsequences

Topological Sort

3620-network-recovery-pathways

Depth-First Search

2492-minimum-score-of-a-path-between-two-cities
2685-count-the-number-of-complete-components
3310-remove-methods-from-project

Union-Find

2492-minimum-score-of-a-path-between-two-cities
3532-path-existence-queries-in-a-graph-i
2685-count-the-number-of-complete-components
2948-make-lexicographically-smallest-array-by-swapping-elements

Sorting

1547-minimum-cost-to-cut-a-stick
1288-remove-covered-intervals
3534-path-existence-queries-in-a-graph-ii
0977-squares-of-a-sorted-array
0015-3sum
0016-3sum-closest
0018-4sum
0581-shortest-unsorted-continuous-subarray
1331-rank-transform-of-an-array
3867-sum-of-gcd-of-formed-pairs
0056-merge-intervals
0628-maximum-product-of-three-numbers
1464-maximum-product-of-two-elements-in-an-array
3517-smallest-palindromic-rearrangement-i
3016-minimum-number-of-pushes-to-type-word-ii
3731-find-missing-elements
2948-make-lexicographically-smallest-array-by-swapping-elements

Greedy

0122-best-time-to-buy-and-sell-stock-ii
3534-path-existence-queries-in-a-graph-ii
0581-shortest-unsorted-continuous-subarray
1081-smallest-subsequence-of-distinct-characters
0316-remove-duplicate-letters
3016-minimum-number-of-pushes-to-type-word-ii
3348-smallest-divisible-digit-product-ii
3302-find-the-lexicographically-smallest-valid-sequence
2029-stone-game-ix
1386-cinema-seat-allocation
3720-lexicographically-smallest-permutation-greater-than-target
2091-removing-minimum-and-maximum-from-array

Math

3754-concatenate-non-zero-digits-and-multiply-by-sum-i
3756-concatenate-non-zero-digits-and-multiply-by-sum-ii
3658-gcd-of-odd-and-even-sums
3867-sum-of-gcd-of-formed-pairs
3312-sorted-gcd-pair-queries
1979-find-greatest-common-divisor-of-array
0202-happy-number
3514-number-of-unique-xor-triplets-ii
0628-maximum-product-of-three-numbers
3518-smallest-palindromic-rearrangement-ii
0486-predict-the-winner
0877-stone-game
1406-stone-game-iii
3345-smallest-divisible-digit-product-i
3348-smallest-divisible-digit-product-ii
1140-stone-game-ii
1510-stone-game-iv
2029-stone-game-ix
1563-stone-game-v
3116-kth-smallest-amount-with-single-denomination-combination
3622-check-divisibility-by-digit-sum-and-product
1872-stone-game-viii
3875-construct-uniform-parity-array-i
3876-construct-uniform-parity-array-ii

String

3756-concatenate-non-zero-digits-and-multiply-by-sum-ii
0844-backspace-string-compare
0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0567-permutation-in-string
0438-find-all-anagrams-in-a-string
0030-substring-with-concatenation-of-all-words
1081-smallest-subsequence-of-distinct-characters
0316-remove-duplicate-letters
3499-maximize-active-section-with-trade-i
3501-maximize-active-section-with-trade-ii
3517-smallest-palindromic-rearrangement-i
0214-shortest-palindrome
3518-smallest-palindromic-rearrangement-ii
3016-minimum-number-of-pushes-to-type-word-ii
3348-smallest-divisible-digit-product-ii
3302-find-the-lexicographically-smallest-valid-sequence
2213-longest-substring-of-one-repeating-character
3090-maximum-length-substring-with-two-occurrences
2904-shortest-and-lexicographically-smallest-beautiful-string
3720-lexicographically-smallest-permutation-greater-than-target
3734-lexicographically-smallest-palindromic-permutation-greater-than-target
0115-distinct-subsequences

Prefix Sum

3756-concatenate-non-zero-digits-and-multiply-by-sum-ii
0209-minimum-size-subarray-sum
3312-sorted-gcd-pair-queries
0560-subarray-sum-equals-k
0724-find-pivot-index
0974-subarray-sums-divisible-by-k
0525-contiguous-array
0862-shortest-subarray-with-sum-at-least-k
1140-stone-game-ii
1872-stone-game-viii
3903-smallest-stable-index-i
3904-smallest-stable-index-ii

Hash Table

3532-path-existence-queries-in-a-graph-i
1331-rank-transform-of-an-array
3312-sorted-gcd-pair-queries
0904-fruit-into-baskets
0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0567-permutation-in-string
0438-find-all-anagrams-in-a-string
0030-substring-with-concatenation-of-all-words
0141-linked-list-cycle
0142-linked-list-cycle-ii
0202-happy-number
0560-subarray-sum-equals-k
0974-subarray-sums-divisible-by-k
0525-contiguous-array
3518-smallest-palindromic-rearrangement-ii
3016-minimum-number-of-pushes-to-type-word-ii
3731-find-missing-elements
2958-length-of-longest-subarray-with-at-most-k-frequency
3090-maximum-length-substring-with-two-occurrences
1386-cinema-seat-allocation
3718-smallest-missing-multiple-of-k
3720-lexicographically-smallest-permutation-greater-than-target
3568-minimum-moves-to-clean-the-classroom

Two Pointers

3534-path-existence-queries-in-a-graph-ii
0167-two-sum-ii-input-array-is-sorted
0082-remove-duplicates-from-sorted-list-ii
0080-remove-duplicates-from-sorted-array-ii
0026-remove-duplicates-from-sorted-array
0977-squares-of-a-sorted-array
0015-3sum
0016-3sum-closest
0018-4sum
0581-shortest-unsorted-continuous-subarray
0844-backspace-string-compare
3867-sum-of-gcd-of-formed-pairs
0567-permutation-in-string
0141-linked-list-cycle
0142-linked-list-cycle-ii
0287-find-the-duplicate-number
0202-happy-number
0876-middle-of-the-linked-list
0143-reorder-list
0986-interval-list-intersections
3302-find-the-lexicographically-smallest-valid-sequence
3734-lexicographically-smallest-palindromic-permutation-greater-than-target

Bit Manipulation

3534-path-existence-queries-in-a-graph-ii
0287-find-the-duplicate-number
3514-number-of-unique-xor-triplets-ii
1386-cinema-seat-allocation
3116-kth-smallest-amount-with-single-denomination-combination
3568-minimum-moves-to-clean-the-classroom

Linked List

0082-remove-duplicates-from-sorted-list-ii
0141-linked-list-cycle
0142-linked-list-cycle-ii
0876-middle-of-the-linked-list
0143-reorder-list
2058-find-the-minimum-and-maximum-number-of-nodes-between-critical-points

Stack

0581-shortest-unsorted-continuous-subarray
0844-backspace-string-compare
0143-reorder-list
1081-smallest-subsequence-of-distinct-characters
0316-remove-duplicate-letters

Monotonic Stack

0581-shortest-unsorted-continuous-subarray
1081-smallest-subsequence-of-distinct-characters
0316-remove-duplicate-letters

Simulation

0844-backspace-string-compare
3867-sum-of-gcd-of-formed-pairs
1260-shift-2d-grid
3069-distribute-elements-into-two-arrays-i

Sliding Window

0209-minimum-size-subarray-sum
0904-fruit-into-baskets
0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0567-permutation-in-string
0438-find-all-anagrams-in-a-string
0030-substring-with-concatenation-of-all-words
0862-shortest-subarray-with-sum-at-least-k
2958-length-of-longest-subarray-with-at-most-k-frequency
3090-maximum-length-substring-with-two-occurrences
2904-shortest-and-lexicographically-smallest-beautiful-string

Enumeration

1291-sequential-digits
3499-maximize-active-section-with-trade-i
3514-number-of-unique-xor-triplets-ii
3345-smallest-divisible-digit-product-i
3720-lexicographically-smallest-permutation-greater-than-target
3734-lexicographically-smallest-palindromic-permutation-greater-than-target

Number Theory

3658-gcd-of-odd-and-even-sums
3867-sum-of-gcd-of-formed-pairs
3312-sorted-gcd-pair-queries
1979-find-greatest-common-divisor-of-array
3348-smallest-divisible-digit-product-ii
3116-kth-smallest-amount-with-single-denomination-combination

Combinatorics

3312-sorted-gcd-pair-queries
3518-smallest-palindromic-rearrangement-ii
3116-kth-smallest-amount-with-single-denomination-combination

Counting

3312-sorted-gcd-pair-queries
3518-smallest-palindromic-rearrangement-ii
3016-minimum-number-of-pushes-to-type-word-ii
2029-stone-game-ix
3720-lexicographically-smallest-permutation-greater-than-target

Recursion

0143-reorder-list
0486-predict-the-winner

Divide and Conquer

0053-maximum-subarray
0918-maximum-sum-circular-subarray
0327-count-of-range-sum

Queue

0918-maximum-sum-circular-subarray
0862-shortest-subarray-with-sum-at-least-k

Monotonic Queue

0918-maximum-sum-circular-subarray
0862-shortest-subarray-with-sum-at-least-k

Binary Indexed Tree

0327-count-of-range-sum

Segment Tree

0327-count-of-range-sum
3501-maximize-active-section-with-trade-ii
2213-longest-substring-of-one-repeating-character

Merge Sort

0327-count-of-range-sum

Ordered Set

0327-count-of-range-sum
2213-longest-substring-of-one-repeating-character

Sweep Line

0986-interval-list-intersections

Counting Sort

3517-smallest-palindromic-rearrangement-i

Rolling Hash

0214-shortest-palindrome

String Matching

0214-shortest-palindrome

Hash Function

0214-shortest-palindrome

Game Theory

0486-predict-the-winner
0877-stone-game
1406-stone-game-iii
1140-stone-game-ii
1510-stone-game-iv
2029-stone-game-ix
1563-stone-game-v
1872-stone-game-viii

Minimax

1406-stone-game-iii
0486-predict-the-winner
1140-stone-game-ii
1510-stone-game-iv
2029-stone-game-ix
1872-stone-game-viii

Zero-Sum Game

1406-stone-game-iii
0486-predict-the-winner
1140-stone-game-ii
1510-stone-game-iv
2029-stone-game-ix
1872-stone-game-viii

Backtracking

3348-smallest-divisible-digit-product-ii

Nim Game

1510-stone-game-iv
2029-stone-game-ix

Sprague–Grundy Theorem

1510-stone-game-iv