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…

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…

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+1+1 = 3+1+1-1+1+1 = 3+1+1+1-1+1 = 3+1+1+1+1-1 = 3一共有5种方法让最终目标和为3.注…

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…

Level:   Medium 题目描述: 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…

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…