LeedCode

Collection of LeetCode questions to ace the coding interview!

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0026-remove-duplicates-from-sorted-array
0066-plus-one
0121-best-time-to-buy-and-sell-stock
0136-single-number
0217-contains-duplicate
0448-find-all-numbers-disappeared-in-an-array
0561-array-partition
0628-maximum-product-of-three-numbers
0792-binary-search
0898-transpose-matrix
1027-sum-of-even-numbers-after-queries
1122-relative-sort-array
1210-mean-of-array-after-removing-some-elements
1319-unique-number-of-occurrences
1470-shuffle-the-array
1574-maximum-product-of-two-elements-in-an-array
1781-check-if-two-string-arrays-are-equivalent
1848-sum-of-unique-elements
1944-truncate-sentence
2058-concatenation-of-array
2093-check-if-string-is-a-prefix-of-array
2106-find-greatest-common-divisor-of-array
2181-smallest-index-with-equal-value
2277-count-equal-and-divisible-pairs-in-an-array
2486-most-frequent-even-element
2542-average-value-of-even-numbers-that-are-divisible-by-three
2585-delete-greatest-value-in-each-row
2624-difference-between-element-sum-and-digit-sum-of-an-array
2634-minimum-common-value
2675-find-the-width-of-columns-of-a-grid
2881-split-strings-by-separator
2942-find-words-containing-character
3028-ant-on-the-boundary
3226-minimum-number-game
3432-count-partitions-with-even-sum-difference
3606-minimum-element-after-replacement-with-digit-sum
3846-minimum-operations-to-make-array-sum-divisible-by-k

Two Pointers

0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0557-reverse-words-in-a-string-iii
2093-check-if-string-is-a-prefix-of-array
2634-minimum-common-value

String

0020-valid-parentheses
0125-valid-palindrome
0242-valid-anagram
0412-fizz-buzz
0520-detect-capital
0557-reverse-words-in-a-string-iii
0657-robot-return-to-origin
0742-to-lower-case
1205-defanging-an-ip-address
1221-split-a-string-in-balanced-strings
1737-maximum-nesting-depth-of-the-parentheses
1781-check-if-two-string-arrays-are-equivalent
1944-truncate-sentence
2093-check-if-string-is-a-prefix-of-array
2346-largest-3-same-digit-number-in-string
2819-remove-trailing-zeros-from-a-string
2881-split-strings-by-separator
2942-find-words-containing-character
3019-furthest-point-from-origin
3636-check-balanced-string

Math

0009-palindrome-number
0066-plus-one
0070-climbing-stairs
0367-valid-perfect-square
0412-fizz-buzz
0507-perfect-number
0628-maximum-product-of-three-numbers
1406-subtract-the-product-and-sum-of-digits-of-an-integer
1806-count-of-matches-in-tournament
2083-three-divisors
2106-find-greatest-common-divisor-of-array
2298-count-integers-with-even-digit-sum
2507-number-of-common-factors
2542-average-value-of-even-numbers-that-are-divisible-by-three
2624-difference-between-element-sum-and-digit-sum-of-an-array
3172-divisible-and-non-divisible-sums-difference
3371-harshad-number
3432-count-partitions-with-even-sum-difference
3606-minimum-element-after-replacement-with-digit-sum
3846-minimum-operations-to-make-array-sum-divisible-by-k

Hash Table

0001-two-sum
0141-linked-list-cycle
0217-contains-duplicate
0242-valid-anagram
0448-find-all-numbers-disappeared-in-an-array
1122-relative-sort-array
1319-unique-number-of-occurrences
1848-sum-of-unique-elements
2486-most-frequent-even-element
2634-minimum-common-value

Binary Search

0004-median-of-two-sorted-arrays
0367-valid-perfect-square
0792-binary-search
2634-minimum-common-value

Stack

0020-valid-parentheses
1737-maximum-nesting-depth-of-the-parentheses

Enumeration

2083-three-divisors
2507-number-of-common-factors

Number Theory

2083-three-divisors
2106-find-greatest-common-divisor-of-array
2507-number-of-common-factors

Sorting

0217-contains-duplicate
0242-valid-anagram
0561-array-partition
0628-maximum-product-of-three-numbers
1122-relative-sort-array
1210-mean-of-array-after-removing-some-elements
1574-maximum-product-of-two-elements-in-an-array
2585-delete-greatest-value-in-each-row
3226-minimum-number-game

Heap (Priority Queue)

1574-maximum-product-of-two-elements-in-an-array
2585-delete-greatest-value-in-each-row
3226-minimum-number-game

Simulation

0412-fizz-buzz
0657-robot-return-to-origin
0898-transpose-matrix
1027-sum-of-even-numbers-after-queries
1806-count-of-matches-in-tournament
2058-concatenation-of-array
2298-count-integers-with-even-digit-sum
2585-delete-greatest-value-in-each-row
3028-ant-on-the-boundary
3226-minimum-number-game

Counting

1221-split-a-string-in-balanced-strings
1848-sum-of-unique-elements
2486-most-frequent-even-element
3019-furthest-point-from-origin

Matrix

0898-transpose-matrix
2585-delete-greatest-value-in-each-row
2675-find-the-width-of-columns-of-a-grid

Linked List

0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0141-linked-list-cycle
0206-reverse-linked-list
0838-design-linked-list

Dynamic Programming

0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0338-counting-bits

Tree

0100-same-tree
0104-maximum-depth-of-binary-tree
0226-invert-binary-tree
0572-subtree-of-another-tree
0975-range-sum-of-bst

Depth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0226-invert-binary-tree
0572-subtree-of-another-tree
0975-range-sum-of-bst

Binary Search Tree

0975-range-sum-of-bst

Binary Tree

0100-same-tree
0104-maximum-depth-of-binary-tree
0226-invert-binary-tree
0572-subtree-of-another-tree
0975-range-sum-of-bst

Recursion

0021-merge-two-sorted-lists
0206-reverse-linked-list

String Matching

0572-subtree-of-another-tree

Hash Function

0572-subtree-of-another-tree

Divide and Conquer

0004-median-of-two-sorted-arrays
0190-reverse-bits
0191-number-of-1-bits

Bit Manipulation

0136-single-number
0190-reverse-bits
0191-number-of-1-bits
0338-counting-bits

Memoization

0070-climbing-stairs

Breadth-First Search

0100-same-tree
0104-maximum-depth-of-binary-tree
0226-invert-binary-tree

Design

0838-design-linked-list

Greedy

0561-array-partition
1221-split-a-string-in-balanced-strings

Prefix Sum

3028-ant-on-the-boundary
3432-count-partitions-with-even-sum-difference

Counting Sort

0561-array-partition
1122-relative-sort-array