二分查找的遞歸與非遞歸

#include<stdio.h>
//循環
int CycleFind(int arr[], int left, int right, int input)
{
    int mid = 0;
    if ((input<arr[left]) && (input>arr[right]))
        return -1;
    while (left <= right)
    {
        mid = left+((right-left)>>1);
        if (input>arr[mid])
            left = mid+1;
        else if (input < arr[mid])
            right = mid - 1;
        else
            break;
    }
    if (left <= right)
        return mid;
    else
        return -1;
}

//遞歸
int RecursiveFind(int arr[], int left, int right, int input)
{
    while(left <= right)
    {
        int mid = left + ((right - left) >> 1);
        if (input == arr[mid])
            return mid;
        else if (input > arr[mid])
            return RecursiveFind(arr, mid + 1, right, input);
        else if (input < arr[mid])
            return RecursiveFind(arr, left, mid - 1, input);
        else
            break;
    }
    return -1;
}
int main()
{
    int arr[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    int input = 7;
    int left = 0;
    int right = sizeof(arr) / sizeof(arr[0]) - 1;
    printf("CycleFind result is %d\n", CycleFind(arr, left, right, input));
    printf("RecursiveFind result is %d\n", RecursiveFind(arr, left, right, input));
    system("pause");
    return 0;
}