二分查找非递归实现--【编程珠玑】

#include <iostream>
#include <cstring>

using namespace std;

int BinarySearch(int* s, int x, int low, int high)
{
    int mid;

    while(low <= high)
    {
        mid = (low + high) / 2;

        if(s[mid] == x)
           return mid;
        else if(s[mid] < x)
           low = mid + 1;
        else high = mid - 1;
    }

    return -1;
}

int main()
{
    int s[] = {0, 3, 5, 7, 11, 14, 16, 34, 50, 65, 70}; //递增序列，也可运用动态数组存数据

    cout<<"请输入需要查找的数：";
    int num;
    cin>>num;

    int n = sizeof(s) / sizeof(int);

    int index = BinarySearch(s, num, 0, n - 1);
    if(index >= 0)  //根据返回值判断是否在数组中
        cout<<"数字"<<num<<"在数组第"<<index + 1<<"个"<<endl;
    else
        cout<<"数字"<<num<<"不在数组中"<<endl;
    return 0;
}