POJ 3061 Subsequence

#include <cstdio>
#include <algorithm>
using namespace std;

const int INF = 0x7fffffff;
const int MAXN = 100000+5;
int a[MAXN];
int n, s;

void solve()
{
    //尺取法
    int l = 0, r = 0;   //初始化左右指针
    int sum = 0, res = INF;
    while(1){
        while(r < n && sum < s){   //不断移动右指针，直到满足条件
            sum += a[r++];
        }
        if(sum < s) //条件无法满足，终止
            break;
        res = min(res, r-l);    //更新结果，相应区间为[l, r)
        sum -= a[l++];  //移动左指针
    }
    printf("%d\n", res == INF ? 0 : res);
}

int main()
{
    int t;
    scanf("%d", &t);
    while(t--){
        scanf("%d%d", &n, &s);
        for(int i = 0; i < n; ++i)
            scanf("%d", &a[i]);
        solve();
    }
    return 0;
}