c++ 二分查找法源代码

#include <vector>
#include <iostream>
using namespace std;

vector<int> data;

void createData(int n){
    //存储小于n的正偶数
    for (int i=0;i<n;i+=2)
        data.push_back(i);
}

bool search(int value,int& sign){
    int start=0;int end=data.size()-1;int mid;
    while(start<=end){
        mid = (end + start)/2;
        if (data.at(mid) == value)
        {
            sign = mid;
            return true;
        }else if (data.at(mid) < value)
        {
            start = mid + 1;
        }else{
            end = mid -1;
        }
    }
    sign = -1;
    return false;
}
int _tmain(int argc, _TCHAR* argv[])
{
    createData(100);
    int sign,ret;
    for (int i=-1;i<120;i+=15)
    {
        ret = search(i,sign);
        cout<<"i="<<i<<"; search返回:"<<ret<<"; sign="<<sign<<endl;
    }
    getchar();
    return 0;
}