Leetcode_hard

A collection of LeetCode questions to ace the coding interview! - Created using LeetHub v2

LeetCode Topics

Hash Table

0264-ugly-number-ii
0692-top-k-frequent-words

Math

0089-gray-code
0189-rotate-array
0264-ugly-number-ii
0313-super-ugly-number
0382-linked-list-random-node
0458-poor-pigs
0878-nth-magical-number

Dynamic Programming

0044-wildcard-matching
0053-maximum-subarray
0123-best-time-to-buy-and-sell-stock-iii
0188-best-time-to-buy-and-sell-stock-iv
0264-ugly-number-ii
0313-super-ugly-number
0435-non-overlapping-intervals
0458-poor-pigs
2035-partition-array-into-two-arrays-to-minimize-sum-difference

Heap (Priority Queue)

0264-ugly-number-ii
0692-top-k-frequent-words
0912-sort-an-array

Array

0004-median-of-two-sorted-arrays
0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0053-maximum-subarray
0123-best-time-to-buy-and-sell-stock-iii
0137-single-number-ii
0188-best-time-to-buy-and-sell-stock-iv
0189-rotate-array
0200-number-of-islands
0260-single-number-iii
0313-super-ugly-number
0435-non-overlapping-intervals
0692-top-k-frequent-words
0912-sort-an-array
2035-partition-array-into-two-arrays-to-minimize-sum-difference
2433-find-the-original-array-of-prefix-xor

Two Pointers

0026-remove-duplicates-from-sorted-array
0061-rotate-list
0189-rotate-array
2035-partition-array-into-two-arrays-to-minimize-sum-difference

Linked List

0061-rotate-list
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0206-reverse-linked-list
0382-linked-list-random-node

Reservoir Sampling

0382-linked-list-random-node

Randomized

0382-linked-list-random-node

String

0020-valid-parentheses
0044-wildcard-matching
0692-top-k-frequent-words
2211-count-collisions-on-a-road

Greedy

0044-wildcard-matching
0435-non-overlapping-intervals
2429-minimize-xor

Recursion

0044-wildcard-matching
0206-reverse-linked-list

Combinatorics

0458-poor-pigs

Sorting

0435-non-overlapping-intervals
0692-top-k-frequent-words
0912-sort-an-array

Stack

0020-valid-parentheses
2211-count-collisions-on-a-road

Trie

0692-top-k-frequent-words

Bucket Sort

0692-top-k-frequent-words
0912-sort-an-array

Counting

0692-top-k-frequent-words

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0912-sort-an-array

Merge Sort

0912-sort-an-array

Radix Sort

0912-sort-an-array

Counting Sort

0912-sort-an-array

Simulation

2211-count-collisions-on-a-road

Tree

0110-balanced-binary-tree
0450-delete-node-in-a-bst
0701-insert-into-a-binary-search-tree

Depth-First Search

0110-balanced-binary-tree
0200-number-of-islands

Binary Tree

0110-balanced-binary-tree
0450-delete-node-in-a-bst
0701-insert-into-a-binary-search-tree

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0878-nth-magical-number
2035-partition-array-into-two-arrays-to-minimize-sum-difference

Binary Search Tree

0450-delete-node-in-a-bst
0701-insert-into-a-binary-search-tree

Breadth-First Search

0200-number-of-islands

Union Find

0200-number-of-islands

Matrix

0200-number-of-islands

Bit Manipulation

0089-gray-code
0137-single-number-ii
0201-bitwise-and-of-numbers-range
0260-single-number-iii
1318-minimum-flips-to-make-a-or-b-equal-to-c
2035-partition-array-into-two-arrays-to-minimize-sum-difference
2429-minimize-xor
2433-find-the-original-array-of-prefix-xor

Ordered Set

2035-partition-array-into-two-arrays-to-minimize-sum-difference

Bitmask

2035-partition-array-into-two-arrays-to-minimize-sum-difference

Backtracking

0089-gray-code