Reverse Integer


Reverse digits of an integer.

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


If the integer’s last digit is 0, what should the output be? ie, cases such as 10, 100. — Assume as 01 and 001

Did you notice that the reversed integer might overflow? Assume the input is a 32-bit integer, then the reverse of 1000000003 overflows. How should you handle such cases? — To return some default value, however leetcode does not have a case that causes overflow.

Throw an exception? Good, but what if throwing an exception is not an option? You would then have to re-design the function (ie, add an extra parameter).


public class Solution {
    public int reverse(int x) {
        String X = Integer.toString(x);
        StringBuilder sb = new StringBuilder();
        int start = 0;
        if (X.charAt(start) == '-') {
        for (int i = X.length() - 1; i >= start; i--) {
        return Integer.valueOf(sb.toString());


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s