168. Excel Sheet Column Title

Easy

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"

 

package leetcode.easy;

public class ExcelSheetColumnTitle {
	@org.junit.Test
	public void test() {
		System.out.println(convertToTitle(1));
		System.out.println(convertToTitle(28));
		System.out.println(convertToTitle(701));
	}

	public String convertToTitle(int n) {
		StringBuffer buffer = new StringBuffer();
		while (n > 0) {
			n--;
			buffer.append((char) ('A' + n % 26));
			n /= 26;
		}
		return buffer.reverse().toString();
	}
}