_168.java

package com.fishercoder.solutions.firstthousand;

/*
*
* 168. Excel Sheet Column Title

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

For example:

1 -> A
2 -> B
3 -> C
...
26 -> Z
27 -> AA
28 -> AB
...

Example 1:

Input: 1
Output: "A"

Example 2:

Input: 28
Output: "AB"

Example 3:

Input: 701
Output: "ZY"

*/
public class _168 {
    public static class Solution1 {
        public String convertToTitle(int n) {
            /*Get the right most digit first, move to the left, e.g. when n = 28, we get 'B' first, then we get 'A'.*/
            StringBuilder sb = new StringBuilder();
            while (n != 0) {
                int temp = (n - 1) % 26;
                sb.append((char) (temp + 65));
                n = (n - 1) / 26;
            }
            return sb.reverse().toString();
        }
    }
}