【C语言】编写一个折半查找函数

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

}