7. Reverse Integer
Easy
Given a 32-bit signed integer, reverse digits of an integer.
Example 1:
Input: 123
Output: 321
Example 2:
Input: -123
Output: -321
Example 3:
Input: 120
Output: 21
Note:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231, 231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
package leetcode;
public class ReverseInteger {
@org.junit.Test
public void test() {
int number1 = 123;
int number2 = -123;
int number3 = 120;
ReverseInteger reverseInteger = new ReverseInteger();
System.out.println(reverseInteger.reverse(number1));
System.out.println(reverseInteger.reverse(number2));
System.out.println(reverseInteger.reverse(number3));
}
public int reverse(int x) {
int rev = 0;
while (x != 0) {
int pop = x % 10;
x /= 10;
if (rev > Integer.MAX_VALUE / 10 || (rev == Integer.MAX_VALUE / 10 && pop > 7)) {
return 0;
}
if (rev < Integer.MIN_VALUE / 10 || (rev == Integer.MIN_VALUE / 10 && pop < -8)) {
return 0;
}
rev = rev * 10 + pop;
}
return rev;
}
}
原文：https://www.cnblogs.com/denggelin/p/11518189.html