Related to question Excel Sheet Column Title 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 ``` public class Solution { public int titleToNumber(String s) { int result = 0; for (int i = 0; i < s.length(); i++) { result = result * 26 + (s.charAt(i) - 'A' + 1); } return result; } } //charAt() 方法返回指定索引處的char值。索引范圍是從0到length() - 1。對于數組索引， 序列的第一個char值是在索引為0，索引1 ```