51nod 1049 最大子段和

51nod 1049 最大子段和

动态规划思想：当前最大子段和是前一个数字结尾的子段和（正数）+当前值，子段和（负数）另起子段。

#include <iostream>#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <queue>#include <map>using namespace std;#define INF 0x3f3f3f3f#define PI acos(-1.0)#define mod 10007#define N 110000int n;int main(){    scanf("%d",&n);    int a;    long long ans = 0;    long long now = 0;    for(int i = 0 ;i < n; i++)    {        scanf("%d",&a);        if(now < 0)            now = a;        else            now += a;        if(now > ans)            ans = now;    }    printf("%lld\n",ans);    return 0;}