题:https://leetcode.com/problems/range-sum-query-immutable/description/ 题目 Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Given nums
题:https://leetcode.com/problems/minimum-path-sum/description/ 题目 Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers
题:https://leetcode.com/problems/sum-of-left-leaves/description/ 题目 Find the sum of all left leaves in a given binary tree. Example: 3/ \9 20/ \15 7There are two left leaves in the binary t
40. Combination Sum II Problem's Link ---------------------------------------------------------------------------- Mean: 给你一个待选集合s和一个数n,选出所有相加之和为n的组合.(每个元素只能选一次) analyse: 递归求解. 在递归进入
39. Combination Sum Problem's Link ---------------------------------------------------------------------------- Mean: 给你一个待选集合s和一个数n,让你找出集合s中相加之和为n的所有组合.(每个数可选多次) analyse: 作此题需对递归有一定的
数据结构MOOC PTA习题 01-复杂度2 Maximum Subsequence Sum #include <iostream>using namespace std;const int M = 100005;int a[M];int main(){int k;cin >> k;int f = 1;for (int i = 0; i < k; i++){cin >> a[i
Given a non-negative integer c, your task is to decide whether there're two integers a and b such that a2 + b2 = c. Example 1: Input: 5Output: TrueExplanation: 1 * 1 + 2 * 2 = 5 Example 2: Inpu
Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. Example 1: Input:nums = [1,1,1], k = 2Output: 2 思路:用prefixsum prefixsu
Given an integer number n, return the difference between the product of its digits and the sum of its digits. Example 1: Input: n = 234Output: 15 Explanation: Product of digits = 2 * 3 * 4 = 24
话不多说,直接举例咋用。 先知道一下常用语法: sum(case 属性名 when 属性值1 then 1 else 0 end),意思就是某个属性下为属性值1就加1个数量,否则就作0统计。 看我的表players的长相: 1、统计男生和女生的数量 SELECT sum(CASE gender WHEN 'man' THEN 1 ELSE 0 END) as man_numbers, su
题目 Path Sum I: Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given th
K Sum Problem Leetcode上有2 sum problem,3 sum problem, 4 sum problem,K sum problem等问题,为方便讨论,从最简单的2 sum入手,讨论到更一般的K sum problem,这类问题一般具有这样的形式: 给定一个n长度的数组array和一个target,在数组中寻找k个数,使这k个数的和等于target,并且
题目 Given an array of positive integers nums and a positive integer target, return the minimal length of a subarray whose sum is greater than or equal to target. If there is no such subarray, return 0
Description Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -. Example: Given a = 1 and b = 2, return 3. 解法 思路: 首先不能用”+”、” - “符号,那么计算两个数的和也就只能用“位运算符”
一,表结构 表一,test_group 分组表 表二,test_user 用户表 test_group 和 test_user 是一对多的关系 二,sql 统计一班的总得分和所有用户的总年龄 SELECT SUM(a.score),SUM(b.age),a.groupname from test_group a LEFT JOIN test_user b on a.id=b.group