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
solution:
Time: O(log(n)) Space: O(log(n))
public class Solution { public String convertToTitle(int A) { int size = 26; StringBuilder sb = new StringBuilder(); int r = 0; while (A / 26 > 0) { r = A % 26; if (r == 0) { r = 26; A -= 26; } sb.append((char) (r + 'A' - 1)); A = A / 26; } r = A % 26; if (r != 0) { sb.append((char) (r + 'A' - 1)); } return sb.reverse().toString(); } }