[LeetCode 171]Excel Sheet Column Number

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 

solution:

26 进制，逐位＊26相加

public int titleToNumber(String s) {        if(s == null ||s.isEmpty()) return 0;        if(s.length()==1) return s.charAt(0)-'A'+1;        int result = s.charAt(0)-'A'+1;        for(int i=1;i<s.length();i++){            int cur = s.charAt(i)-'A'+1;            result = result*26 + cur;        }        return result;    }