leetcode

LeetCode notes on the Longest Common Substring problem.

LeetCode notes on the Longest Common Subsequence problem.

LeetCode notes on the longest substring without repeating characters.

LeetCode notes on the Edit Distance problem.

LeetCode notes on the Next Permutation problem.

LeetCode notes on the Permutations problem.

LeetCode notes on the Subsets problem.

LeetCode notes on the Unique Paths problem.

LeetCode notes on the Number of Islands problem.

LeetCode notes on the Maximal Square problem.

Course Schedule problem using DFS and BFS topological sorting.

LeetCode notes on the Partition Equal Subset Sum problem.

Word Break using DFS and DFS with memoization.

LeetCode notes on the Perfect Squares problem.

Word search in a two-dimensional grid using DFS.

LeetCode notes on the Target Sum problem.

A note for the longest common substring problem.

LeetCode notes on the Combination Sum problem.

Design an LRU cache with a map and a doubly linked list, with Go and Java implementations.

LeetCode notes on the Coin Change problem.

Longest common subsequence using recursion, DFS with memoization, and dynamic programming.

LeetCode notes on the Burst Balloons problem.

Letter combinations of a phone number using DFS to enumerate combinations.

LeetCode notes on the House Robber problem.

Edit distance using recursion and recursion with memoization.

LeetCode notes on the Best Time to Buy and Sell Stock with Cooldown problem.

Group anagrams using a brute-force method and hashing.

LeetCode notes on the Minimum Path Sum problem.

Find all anagrams in a string using brute force and a sliding window with counts.

LeetCode notes on the Longest Increasing Subsequence problem.

Longest common prefix using a brute-force approach, with a trie idea noted.

LeetCode notes on the Jump Game problem.

LeetCode notes on the Maximum Product Subarray problem.

Check whether a string is a palindrome using reversal and two pointers.

LeetCode notes on the Maximum Subarray problem.

A Go implementation for reversing a string.

LeetCode notes on the First Missing Positive problem.

Count palindromic substrings using brute force and center expansion.

LeetCode notes on the 3Sum problem.

LeetCode notes on the Find the Duplicate Number problem.

Longest palindromic substring using brute force and center expansion.

LeetCode notes on the Two Sum problem.

LeetCode notes on finding all disappeared numbers in an array.

Add large numbers represented as strings by scanning from right to left and carrying.

LeetCode notes on the Subarray Sum Equals K problem.

LeetCode notes on the Longest Consecutive Sequence problem.

Decode strings in k[encoded_string] form using a stack.

Use a stack to mark matched parentheses, then count the longest consecutive valid interval.

Enumerate whether to keep or remove each character, then keep the longest valid-parentheses results.

Generate parentheses using full enumeration with a stack, and pruning based on remaining left/right parentheses.

Validate a parentheses sequence using a stack or repeated string replacement.

Regular expression matching with support for . and *.

LeetCode notes on binary-search upper bound.

Find the longest substring without repetition using a brute-force set approach and a sliding window.

LeetCode notes on finding the first and last position of an element in a sorted array.

Use weighted union-find to evaluate division relationships between variables.

Count the number of 1 bits in every integer from 0 through num.

Compute the Hamming distance between two integers using bitwise operations.

LeetCode notes on binary-search upper bound.

Reverse the decimal digits of a 32-bit signed integer and handle overflow.

LeetCode notes on finding the first and last position of an element in a sorted array.

Count the ways to climb stairs using a Fibonacci recurrence.

LeetCode notes on searching in a rotated sorted array.

LeetCode notes on searching in a rotated sorted array.

Merge two sorted integer arrays into one sorted array.

LeetCode notes on the Find Peak Element problem.

Find the K-th largest element in an array using sorting or quicksort partitioning.

Use binary search to find a target value in a sorted ascending integer array.

LeetCode notes on finding the minimum in a rotated sorted array.

LeetCode notes on computing an integer square root.

Traverse a matrix in clockwise spiral order.

Find the smallest letter greater than the target in a cyclically ordered character list.

LeetCode notes on the Trapping Rain Water problem.

LeetCode notes on the Container With Most Water problem.

Sort first and then insert by position to reconstruct a queue described by height and preceding-person counts.

Rearrange non-negative integers so their concatenation forms the largest integer.

Find the top K frequent elements using frequency counting with sorting or a min-heap.

Find the majority element using a counting map or candidate cancellation.

Find the element that appears only once using counting or XOR.

Move all zeroes to the end of the array while preserving the relative order of non-zero elements.

Compute the product of array elements except self using left and right product arrays.

Sort 0, 1, and 2 in place using quicksort, bucket sort, or the move-zeroes idea.

Search a matrix whose rows and columns are both sorted, starting from the top-right corner.

LeetCode notes on the Maximum Product Subarray problem.

LeetCode notes on the brute-force solution for Subarray Sum Equals K.

LeetCode notes on the brute-force solution for Maximal Square.

LeetCode notes on the brute-force solution for Daily Temperatures.

LeetCode notes on Daily Temperatures with brute force and a monotonic stack.

LeetCode notes on Sliding Window Maximum using brute force, a priority queue, and a monotonic deque.

LeetCode notes on merging overlapping intervals.

LeetCode notes on implementing a stack that retrieves the minimum element in constant time.

LeetCode notes on sorting an array with merge sort and quicksort.

LeetCode notes on finding the median of two sorted arrays by merging them.

LeetCode notes on the Jump Game problem.

LeetCode notes on finding the shortest continuous subarray that must be sorted.

LeetCode notes on maximizing profit from one stock transaction.

LeetCode notes on rotating an n x n matrix 90 degrees clockwise.

LeetCode notes on implementing a Trie prefix tree.

LeetCode notes on counting unique binary search trees with DFS, memoization, and dynamic programming.

LeetCode notes on binary tree inorder traversal with recursion and color marking.

LeetCode notes on reconstructing a binary tree from preorder and inorder traversals.

Notes on implementing preorder, inorder, and postorder traversal of a binary tree.

LeetCode notes on converting a binary search tree to a Greater Sum Tree.

LeetCode notes on validating a binary search tree with inorder traversal.

LeetCode notes on flattening a binary tree into a linked list in preorder.

LeetCode notes on finding the lowest common ancestor in a binary tree.

LeetCode notes on calculating the diameter of a binary tree.

Notes on finding the lowest common ancestor of two nodes in a binary tree.

LeetCode notes on merging two binary trees.

LeetCode notes on checking whether a binary tree is mirror-symmetric.

LeetCode notes on House Robber III using DFS and memoization.

LeetCode notes on summing all numbers formed by root-to-leaf paths.

LeetCode notes on Invert Binary Tree.

LeetCode notes on Path Sum III.

LeetCode notes on Maximum Depth of Binary Tree.

LeetCode notes on Binary Tree Maximum Path Sum.

LeetCode notes on Binary Tree Right Side View.

LeetCode notes on Binary Tree Level Order Traversal.

LeetCode notes on Serialize and Deserialize Binary Tree.

LeetCode notes on Binary Tree Zigzag Level Order Traversal.

LeetCode notes on Swap Nodes in Pairs.

LeetCode notes on Reverse Linked List II.

LeetCode notes on Reverse Linked List.

LeetCode notes on Reverse Nodes in k-Group.

LeetCode notes on Add Two Numbers.

LeetCode notes on Remove Duplicates from Sorted List II.

LeetCode notes on Remove Duplicates from Sorted List.

LeetCode notes on Remove Nth Node From End of List.

LeetCode notes on Palindrome Linked List.

LeetCode notes on Palindrome Linked List.

LeetCode notes on Linked List Cycle.

LeetCode notes on Linked List Cycle II.

LeetCode notes on Rotate List.

LeetCode notes on Linked List Cycle.

LeetCode notes on Linked List Cycle II.

LeetCode notes on Intersection of Two Linked Lists.

LeetCode notes on Reorder List.

LeetCode notes on Partition List.

LeetCode notes on Merge k Sorted Lists.

LeetCode notes on Merge Two Sorted Lists.

LeetCode notes on Odd Even Linked List.

LeetCode notes on Sort List.

LeetCode notes on Intersection of Two Linked Lists.