【C语言】二分法查找

二分法查找：

#include<stdio.h>

int binary_search(int arr[],int key,int sz)
{
int left = 0;
int right = sz-1;
while(left<=right)
{
int mid = left + ((right-left)>>1);

if(arr[mid]>key)
{
right = mid - 1;
}
else if(arr[mid]<key)
{
left = mid + 1;
}
else
{
return mid;
}
}
return -1;
}
int main()
{
int arr[] = {1,2,3,4,5,6,7,8,9,10};
int key = 8;
int sz = sizeof(arr)/sizeof(arr[0]);
int ret = binary_search(arr,key,sz);
if(ret== -1)
{
printf("没找到\n");
}
else
{
printf("%d\n",ret);

}
system("pause");
return 0;

}