【leetcode】7. Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

特殊情况：

超过了Int最大范围返回0，小于int最小值返回0

	public int reverse(int x) {
		
		final int MAX = 0x7fffffff;
		final int MIN = 0x80000000;
		long sum = 0;
		
		if(x == 0)
			return x;
		while( x != 0)
		{
			int t = x % 10; // 得到个位
			sum  = 10 * sum + t;
			if( sum < MIN || sum > MAX)
			{
				return 0;
			}
			x = x / 10;
		}
		return (int) sum;
	}