Maximum Subarray Sum

题目描述

Given an array of n integers, your task is to find the maximum sum of values in a contiguous, nonempty subarray.

输入

The first input line has an integer n(): the size of the array.
The second line has n integers x1,x2,...,xn(): the array values.

输出

Print one integer: the maximum subarray sum.

样例输入

8
-1 3 -2 5 3 -5 2 2

样例输出

9

代码

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n;
int main(){ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);cin>>n;vector<ll>x(n+1);vector<ll>current_sum(n+1);vector<ll>max_sum(n+1);ll l=0;for(ll i=1;i<=n;i++){cin>>x[i];if(i==1){current_sum[i]=x[i];max_sum[i]=x[i];}else{current_sum[i]=l+x[i];max_sum[i]=max(current_sum[i],max_sum[i-1]);}l=max(current_sum[i],(ll)0);}cout<<max_sum[n];return 0;
}