写一个函数能够对整型数组进行二分查找

#include<stdio.h>int  binary_search(int arr[], int key, int left, int right){int mid = 0;while (left <= right){mid = left - (left - right) / 2;if (key <arr[mid]){right = mid - 1;}else if (key > arr[mid]){left = mid + 1;}else{return mid;}}if (left > right){return -1;}}int main(){int arr[] = {1,2,3,4,5,6,7,8,9,10};int key = 5;int ret = binary_search(arr, key,  4,8);if (ret != -1){printf("%d\n",ret);}else{printf("不存在\n");}system("pause");return 0;}