原题链接在这里:https://leetcode.com/problems/target-sum/description/ 题目: You are given a list of non-negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols + and -. For each integer, you should choose one from + and - as its new symbol.…

You are given a list of non-negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols + and -. For each integer, you should choose one from + and - as its new symbol. Find out how many ways to assign symbols to make sum of integers…

Question You are given a list of non-negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols + and -. For each integer, you should choose one from + and - as its new symbol. Find out how many ways to assign symbols to make sum of…

Leetcode之深度优先搜索(DFS)专题-494. 目标和(Target Sum) 深度优先搜索的解题详细介绍,点击 给定一个非负整数数组,a1, a2, ..., an, 和一个目标数,S.现在你有两个符号 + 和 -.对于数组中的任意一个整数,你都可以从 + 或 -中选择一个符号添加在前面. 返回可以使最终数组和为目标数 S 的所有添加符号的方法数. 示例 1: 输入: nums: [1, 1, 1, 1, 1], S: 3 输出: 5 解释: -1+1+1+1+1 = 3 +1-1+1…

You are given a list of non-negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols + and -. For each integer, you should choose one from + and - as its new symbol. Find out how many ways to assign symbols to make sum of integers…

lc 494 Target Sum 494 Target Sum You are given a list of non-negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols + and -. For each integer, you should choose one from + and - as its new symbol. Find out how many ways to assign…

2018-07-08 13:24:31 一.525. Contiguous Array 问题描述: 问题求解: 我们都知道对于subarray的问题,暴力求解的时间复杂度为O(n ^ 2),问题规模已经给出是50000量级,显然只能是O(n),至多O(nlogn)的复杂度. 本题使用DP和滑动数组都比较棘手,这才是最麻烦的地方,我们知道一般来说对于subarray的问题,dp和滑动数组是两大利器,但是本题这两个最实用的解法都不再适用,那么该如何解决呢? 其实想通了就是一个很简单的问题,本题是lo…

LeetCode:Path Sum 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 the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \…

Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited number of times. Note: All numbers (including target) will…

剑指offer 65. 不用加减乘除做加法(Leetcode 371. Sum of Two Integers) https://leetcode.com/problems/sum-of-two-integers/ 题目: 写一个函数,求两个整数之和,要求在函数体内不得使用加减乘除这四个符号. 分析: 对于不能使用正常的四则运算符,一般就是使用位运算了.而本题要想实现加法,只能使用异或了. 需要注意的是,加法的时候涉及进位,而进位的实现利用与运算. 此外,进位之后还有可能产生进位,所以要在循环里…