171. Excel Sheet Column Number

Link

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

For example:

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

Example 1:

Input: "A"
Output: 1

Example 2:

Input: "AB"
Output: 28

Example 3:

Input: "ZY"
Output: 701

Solution

    public static String convertToTitle(int n) {
        int modresult = 0;
        StringBuilder sb = new StringBuilder();
        while(n != 0){
            n--;
            modresult = n%26;
            sb.append((char)(modresult + 'A'));
            n = n/26;
        }
        sb.reverse();
        return sb.toString();
    }