1044. Shopping in Mars (25)-PAT甲级真题（二分查找）

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;
}