编程实现两个正整数的除法，当然不能用除法操作符。

int div(const int x, const int y)
{
	int left_num = x;
	int result = 0;
	while (left_num >= y)
	{
		int multi = 1;
		while (y * multi <= (left_num >> 1))
		{
			multi = multi << 1;
		}
		result += multi;
		left_num -= y * multi;
	}
	return result;
}