原创 LeetCode 1110. Delete Nodes And Return Forest(java)

Given the root of a binary tree, each node in the tree has a distinct value. After deleting all nodes with a value

2020-06-20 12:21:35

原创 LeetCode 1111. Maximum Nesting Depth of Two Valid Parentheses Strings(java)

A string is a valid parentheses string (denoted VPS) if and only if it consists of “(” and “)” characters only, and

2020-06-20 12:21:35

原创 LeetCode 1040. Moving Stones Until Consecutive II(java)

On an infinite number line, the position of the i-th stone is given by stones[i]. Call a stone an endpoint stone i

2020-06-20 11:10:18 1

原创 LeetCode1033. Moving Stones Until Consecutive(java)

Three stones are on a number line at positions a, b, and c. Each turn, you pick up a stone at an endpoint (ie., eit

2020-06-20 11:10:08

原创 KMP算法：兩個字符串的匹配，S1裏匹配S2

通過創建一個部分匹配表來優化指針後移的效率。 http://www.ruanyifeng.com/blog/2013/05/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm.html

2020-06-20 11:10:08

原创 432. All O`one Data Structure（java）

Implement a data structure supporting the following operations: Inc(Key) - Inserts a new key with value 1. Or incre

2020-06-20 11:10:08

原创 390. Elimination Game（約瑟夫環）

There is a list of sorted integers from 1 to n. Starting from left to right, remove the first number and every othe

2020-06-20 11:10:08

原创 685. Redundant Connection II(java)

In this problem, a rooted tree is a directed graph such that, there is exactly one node (the root) for which all ot

2020-06-20 11:10:08

原创 684. Redundant Connection(java)

In this problem, a tree is an undirected graph that is connected and has no cycles. The given input is a graph that

2020-06-20 11:10:07

原创 647. Palindromic Substrings(java)

Given a string, your task is to count how many palindromic substrings in this string. The substrings with different

2020-06-20 11:10:07

原创 二進制作爲hashset存放visited,獲取和設置第n位的值

獲取x第n位的值：（x>>n） & 1 設置x第n位的值爲1：x = x || 1<<n

2019-09-15 16:51:38

原创 LeetCode 815. Bus Routes(java)

We have a list of bus routes. Each routes[i] is a bus route that the i-th bus repeats forever. For example if route

2019-09-09 16:50:54 1

原创 53. Maximum Subarray(寫1186順便複習一下這道題的兩種寫法)

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest su

2019-09-09 16:50:54 1

原创 LeetCode 1186. Maximum Subarray Sum with One Deletion(java)

Given an array of integers, return the maximum sum for a non-empty subarray (contiguous elements) with at most one

2019-09-09 16:50:54 1

原创 LeetCode 743. Network Delay Time(Dijistra算法)

There are N network nodes, labelled 1 to N. Given times, a list of travel times as directed edges times[i] = (u, v,

2019-09-08 16:47:51 1