c++primer-p100.用迭代器进行二分法搜索

#include <vector>
#include <iostream>
using namespace std;
int main()
{
	vector<int> text{1,2,3,4,5,6,7,8,9,10};
	int sought;
	cin>>sought;
	//迭代器二分搜索,text必须有序
	auto beg=text.begin(),end=text.end();
	auto mid=beg+(end-beg)/2;
	while(mid!=end&&*mid!=sought){
		if(sought<*mid)
			end=mid;
		else
			beg=mid+1;
		mid=beg+(end-beg)/2;
	}
	if(mid==end)
		cout<<"not found.\n";
	else
		cout<<*mid<<" is found.\n";
	return 0;
}