二分答案 浮点数高精模板

double l = 0, r = inf, mid; 
	while (r - l > 0.001) 
	{
		mid = (l + r) / 2.0;
		int c = 0; 
		for (int i = 0; i < n; i++)
		{
			c += int(arr[i] / mid);
		}
		if (c >= k)
			l = mid;
		else
			r = mid; 
	}