二分查找詳解

int search(int *arr,int size,int key)
{
	assert(arr !=NULL);
	assert(size>0);
	int high=size-1;
	int low=0;
	while(low <=high)
	{
		int mod=low+(high-low)/2;
		if(arr[mod]==key)
			return mod;
		if(key <arr[mod])
			high=mod;
		else
			low=mod+1;
	}
	return -1;
}