二分法查找

binsearch.cpp

#include<iostream>
using namespace std;

bool bin_search(int nums[],int i,int len){
    int left=0,right=len-1,middle;
    while(left<=right){
        middle=left+((right-left)>>1);
        if(i>nums[middle]){
            left=middle+1;
        }else if(i<nums[middle]){
            right=middle-1;
        }else return true;
    }
    return false;
}