C语言习题16

写一个函数，实现一个整形有序数组的二分查找

//数组传参，传过去的不是整个数组，而是第一个元素的地址

#include <stdio.h>                         
int binSearch(int arr[], int size, int x)
{
  int left = 0;
  int right = size - 1;
  int mid = 0;
  while (left <= right)
  {
    mid = left + ((right - left) / 2);
    if (x < arr[mid])
    {
      right = mid - 1;
    }
    else if (x > arr[mid])
    {
      left = mid + 1;
    }
    else 
    {
      return mid;
    }
   }
   return -1;
 }
 int main()
 {
   int arr[] = {1,2,3,4,5,6,7,8,9};
   int size = sizeof(arr) / sizeof(arr[0]);
   int x = 6;
   int index = binSearch(arr, size, x);
   if (index < 0)
   {
     printf("not fonud!\n");
     return 1;
   }
   printf("found it:%d\n",index);
   return 0;
 }