Reverse digits of an integer.
Example1: x = 123, return 321
Example2: x = -123, return -321
思路:int的题,就会有益处,然后处理方法就是采用long来防止益处,然后再判断是否超出范围。
class Solution {
public int reverse(int x) {
int sign = x < 0 ? -1 : 1;
int num = Math.abs(x);
long reverse = 0;
while(num != 0) {
reverse = reverse * 10 + (num % 10);
num = num / 10;
}
if(reverse > Integer.MAX_VALUE || reverse < Integer.MIN_VALUE) {
return 0;
}
return (int)reverse * sign;
}
}