C 语言 二分法 查找。

#include 
int BinarySearch ( int a [], int n , int key ){
	int left =0;
	int right = n -1;
	int mid =0;
	while ( left <= right ){
		mid = left +( right - left )/2;
		if ( key < a [ mid ]){
			 right = right -1; continue ;}
	 	if ( key > a [ mid ]){
	 		left = left +1; continue ;}
	 	if ( key == a [ mid ]){
	 	return mid ;}
 }
	return -1;
}
int main()
{
	int a[5]={1,2,3,4,5};
	
	int t=BinarySearch(a,5,3);
	
	printf("index:%d\n",t);
		 
 
	return 0;
}