https://blog.csdn.net/liuchuo/article/details/54428567
#include<iostream>
#include<vector>
#include<stdio.h>
using namespace std;
int n,m;
vector<int>res,sum;
void fun(int i,int &j,int &tmp){
int l= i,r =n;
while(l<r){
int mid = (r+l)/2;
if(sum[mid] - sum[i-1]>=m) r = mid; //二分查找不能l和r在更新时都 = mid 这里l =mid+1,将大于和小于合在一起，选择大于等于最小花费的位置，
else l = mid+1;
}
j = r;
tmp = sum[j] - sum[i-1];
}
int main(){
cin>>n>>m;
sum.resize(n+1);
for(int i=1;i<=n;i++){
cin>>sum[i];
sum[i]+=sum[i-1];
}
int minres = sum[n];
for(int i=1;i<=n;i++){
int j,tmp;
fun(i,j,tmp);
if(tmp>minres||tmp<m)continue;
else if(tmp<= minres){
if(tmp<minres){
res.clear();
minres =tmp;
}
res.push_back(i);
res.push_back(j);
}
}
for(auto i = 0;i<res.size();i+=2){
printf("%d-%d\n",res[i],res[i+1]);
}
return 0;
}