poj3061 Subsequence

/*
    求出前缀和，然后枚举区间起点 
    区间起点固定下来了之后，终点位置二分查找 
    不要忘了输出0的情况 
*/
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
using namespace std;
#define maxn 100010
int t,n,a[maxn],sum[maxn],s;
int main(){
    //freopen("Cola.txt","r",stdin);
    scanf("%d",&t);
    while(t--){
        memset(a,0,sizeof(a));
        memset(sum,0,sizeof(sum));
        scanf("%d%d",&n,&s);
        for(int i=1;i<=n;i++){
            scanf("%d",&a[i]);
            sum[i]=sum[i-1]+a[i];
        }
        if(sum[n]<s){printf("0\n");continue;}
        int ans=n;
        for(int i=1;i<=n;i++){//枚举起点 
            int l=i,r=n;//二分中点 
            while(l<=r){
                int mid=(l+r)>>1;
                int now=sum[mid]-sum[i-1];
                if(now>=s)r=mid-1,ans=min(ans,mid-i+1);
                else l=mid+1;
            }
        }
        printf("%d\n",ans);
    }
}

/*
    尺取法：
    1.初始化s,t,sum
    2.只要依然有sum<m,就不断将sum加a[t],并将t加1
    3.如果（2）中无法满足sum>=m则终止。否则更新ans
    4.将sum减去a[s],s加1然后回到2 
    像区间右移 
*/
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
#define maxn 100010
int T,n,t,a[maxn],s,m,sum;
int main(){
    scanf("%d",&T);
    while(T--){
        s=1;t=0;
        sum=0;
        bool flag=0;
        scanf("%d%d",&n,&m);
        int ans=n;
        for(int i=1;i<=n;i++)scanf("%d",&a[i]);
        while(1){
            while(t<n&&sum<m)
                sum+=a[++t];
            if(sum<m)break;
            ans=min(ans,t-s+1);flag=1;
            sum-=a[s];s++;
        }
        if(flag==0){printf("0\n");continue;}
        else printf("%d\n",ans);
    }
    return 0;
}