_168.java

package com.fishercoder.solutions;
/**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 */
public class _168 {

    public String convertToTitle_accepted_more_beautiful(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();

    }

    public static void main(String... strings) {
        _168 test = new _168();
//        int n = 28899;
//        int n = 1;
//        int n = 1000000001;
//        int n = 26;
//        int n = 27;
        int n = 28;
//        int n = 52;
//        int n = 53;
//        System.out.println((int) 'A');
//        System.out.println(1000000001/26);
//        System.out.println(25*26);
//        System.out.println(26*26);
//        System.out.println(27*26);
//        System.out.println(702%26);
//        System.out.println(702/26);
        System.out.println(Integer.parseInt(String.valueOf(26), 10));
        System.out.println(test.convertToTitle_accepted_more_beautiful(n));
    }

    public String convertToTitle_accepted(int n) {
        /**'Z' is the corner case, so we'll have to special case handling specially, also, we'll have to do (n-1)/26,
         * only when this is not equal to 1, we'll continue.*/
        StringBuilder sb = new StringBuilder();
        while (n != 0) {
            int temp = n % 26;
            if (temp == 0) {
                sb.append("Z");
            } else {
                sb.append((char) (temp + 64));
            }
            n = (n - 1) / 26;
        }
        return sb.reverse().toString();
    }

}