学习C语言---二分查找

int search(int* arr, int left ,int right ,int parameter)
{
//    int mid = (left + right)/2;
//    看了鹏哥的视频，发现这样会更好一点，防止超出。
    int mid = left + (right - left)/2;
    if(arr[mid] == parameter)
    {
        return mid;
    }
    else if(arr[mid] > parameter)
    {
        right = mid - 1;
        return search(arr,left,right,parameter);
    }
    else if(arr[mid] < parameter)
    {
        left = mid + 1;
        return search(arr,left,right,parameter);
    }

}

int BinarySearch(int* arr, int len, int parameter)
{
    int left = 0;
    int right = len -1;

    return search(arr,left,right,parameter);
}

int main()
{
    int arr[] = {1,2,3,4,5,6,7,8,9,10};
    int len = sizeof(arr)/ sizeof(arr[0]);
    int parameter = 4;
    int index = BinarySearch(arr,len,parameter);
    printf("%d 对应的索引值为：%d\n",parameter,index);

    return 0;
}