原创 LeetCode No.91 Decode Ways
A message containing letters from A-Z is being encoded to numbers using the following mapping: 'A' -> 1 'B' -> 2 ... '
2020-06-28 21:14:37
原创 LeetCode No.100 Same Tree
Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if
2020-06-28 21:14:37
1
原创 LeetCode No.51 N-Queens
The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.
2020-06-28 21:14:37
原创 LeetCode No.80 Remove Duplicates from Sorted Array II
Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array nums
2020-06-28 21:14:26
原创 LeetCode No.258 Add Digits
Given a non-negative integer num, repeatedly add all its digits until the result has only one digit. For example: Gi
2020-06-28 21:14:26
原创 LeetCode No.223 Rectangle Area
Find the total area covered by two rectilinear rectangles in a 2D plane. Each rectangle is defined by its bottom left
2020-06-28 21:14:26
原创 LeetCode No.453 Minimum Moves to Equal Array Elements
Given a non-empty integer array of size n, find the minimum number of moves required to make all array elements equal
2020-06-28 21:14:23
原创 LeetCode No.448 Find All Numbers Disappeared in an Array
Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once.
2020-06-28 21:14:23
原创 LeetCode No.52 N-Queens II
Follow up for N-Queens problem. Now, instead outputting board configurations, return the total number of distinct s
2020-02-23 12:54:45
原创 LeetCode No.303 Range Sum Query - Immutable
Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Giv
2020-02-23 12:54:45
原创 LeetCode No.225 Implement Stack using Queues
Implement the following operations of a stack using queues. push(x) -- Push element x onto stack.pop() -- Removes the
2020-02-23 12:54:45
原创 LeetCode No.173 Binary Search Tree Iterator
Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.
2020-02-23 12:54:45
原创 LeetCode No.171 Excel Sheet Column Number
Related to question Excel Sheet Column Title Given a column title as appear in an Excel sheet, return its correspon
2020-02-23 12:54:45
原创 LeetCode No.231 Power of Two
Given an integer, write a function to determine if it is a power of two. ============================================
2020-02-23 12:54:45
原创 LeetCode No.168 Excel Sheet Column Title
Given a positive integer, return its corresponding column title as appear in an Excel sheet. For example: 1 -> A
2020-02-23 12:54:45