代码

/*********************************************************************
    $AUTHOR$: GalenoJiao
    $DATETIME$: 2024/7/19 11:00:38
*********************************************************************/
int binary_search(const unsigned *a, int n, unsigned x){
	int l = -1, r = n;// a[0,l]<x a[r,n)>x
	while(r-l>1){
		int mid = (r+l)>>1;
		if(a[mid]==x){
			return mid;
		}else if(a[mid]>x){
			r = mid;
		}else{
			l = mid;
		}
	}
	return l;
}

评测结果