尺取法

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<cstdlib>
#include<algorithm>
using namespace std;
int n,S,sum,a[1010];
int main()
{
    int t=0,s=0,res;
    scanf("%d%d",&n,&S);
    res=n+1;
    for(int i=0;i<n;i++)
        scanf("%d",&a[i]);
    for(;;)
    {
        while(t<n&&sum<S)
        {
            sum+=a[t++];
        }
        if(sum<S)
            break;
        res=min(res,t-s);
        sum-=a[s++];
    }
    if(res>n)
        res=0;
    printf("%d\n",res);
    return 0;
}