几种典型查找算法的实现 编程实现：利用折半查找算法实现在数据序列{2,3,6,33,45,66,88,100}分别查找关键字6和89的结果，找到输出位序，找不到输出相应提示信息。vs2010

以下是利用折半查找算法实现在数据序列{2,3,6,33,45,66,88,100}分别查找关键字6和89的代码：

#include <iostream>
using namespace std;

int binarySearch(int arr[], int n, int key)
{
    int left = 0, right = n - 1;
    while (left <= right)
    {
        int mid = (left + right) / 2;
        if (arr[mid] == key)
        {
            return mid;
        }
        else if (arr[mid] > key)
        {
            right = mid - 1;
        }
        else
        {
            left = mid + 1;
        }
    }
    return -1;
}

int main()
{
    int arr[] = {2, 3, 6, 33, 45, 66, 88, 100};
    int n = sizeof(arr) / sizeof(arr[0]);

    int key1 = 6;
    int index1 = binarySearch(arr, n, key1);
    if (index1 != -1)
    {
        cout << "关键字 " << key1 << " 的位置是：" << index1 << endl;
    }
    else
    {
        cout << "未找到关键字 " << key1 << endl;
    }

    int key2 = 89;
    int index2 = binarySearch(arr, n, key2);
    if (index2 != -1)
    {
        cout << "关键字 " << key2 << " 的位置是：" << index2 << endl;
    }
    else
    {
        cout << "未找到关键字 " << key2 << endl;
    }

    return 0;
}

输出结果为：

关键字 6 的位置是：2
未找到关键字 89