LeetCode Weekly Contest 8 415. Add Strings User Accepted: 765 User Tried: 822 Total Accepted: 789 Total Submissions: 1844 Difficulty: Easy Given two non-negative numbers num1 and num2 represented as string, return the sum of num1 and num2. Note: The…

Weekly Contest 86 A:840. 矩阵中的幻方 3 x 3 的幻方是一个填充有从 1 到 9 的不同数字的 3 x 3 矩阵,其中每行,每列以及两条对角线上的各数之和都相等. 给定一个由整数组成的 N × N 矩阵,其中有多少个 3 × 3 的 “幻方” 子矩阵?(每个子矩阵都是连续的). 直接模拟即可,本来是签到题,由于粗心,浪费了时间. class Solution { public: int numMagicSquaresInside(vector<vector<int&…

leetcode weekly contest 43 leetcode649. Dota2 Senate leetcode649.Dota2 Senate 思路: 模拟规则round by round. class Solution { public: string predictPartyVictory(string senate) { int len = senate.size(); int r = 0; int d = 0; int i = 0; while(1) { if(senate[…

LeetCode Weekly Contest 23 1. Reverse String II Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there are less than k characters left, reverse all of them.…

We are given non-negative integers nums[i] which are written on a chalkboard.  Alice and Bob take turns erasing exactly one number from the chalkboard, with Alice starting first.  If erasing a number causes the bitwise XOR of all the elements of the…

We are given non-negative integers nums[i] which are written on a chalkboard.  Alice and Bob take turns erasing exactly one number from the chalkboard, with Alice starting first.  If erasing a number causes the bitwise XOR of all the elements of the…

We are given non-negative integers nums[i] which are written on a chalkboard.  Alice and Bob take turns erasing exactly one number from the chalkboard, with Alice starting first.  If erasing a number causes the bitwise XOR of all the elements of the…

黑板游戏: We are given non-negative integers nums[i] which are written on a chalkboard. Alice and Bob take turns erasing exactly one number from the chalkboard, with Alice starting first. If erasing a number causes the bitwise XOR of all the elements of…

第一题:柠檬水找零 问题: 在柠檬水摊上,每一杯柠檬水的售价为 5 美元. 顾客排队购买你的产品,(按账单 bills 支付的顺序)一次购买一杯. 每位顾客只买一杯柠檬水,然后向你付 5 美元.10 美元或 20 美元.你必须给每个顾客正确找零,也就是说净交易是每位顾客向你支付 5 美元. 注意,一开始你手头没有任何零钱. 如果你能给每位顾客正确找零,返回 true ,否则返回 false . 示例 1: 输入:[5,5,5,10,20] 输出:true 解释: 前 3 位顾客那里,我们按顺序收…

链接:https://leetcode.com/contest/leetcode-weekly-contest-33/ A.Longest Harmonious Subsequence 思路:hash加查找 class Solution { public: int findLHS(vector<int>& nums) { if (nums.empty()) ; ; int len = nums.size(); unordered_map<int, int> hash(len…