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 
题意：给定Excel表格中的某一列标题，返回其在Excel表格中相对应的列数
思路：相当于26进制转10进制。跟Excel Sheet Column Title一题相对应。

public int titleToNumber(String s) {
        int n = 0;
        int temp = 1;
        char[] ch = s.toCharArray();
        for(int i = ch.length - 1; i >= 0; i--){
            n = n + (ch[i] - 'A' + 1) * temp;
            temp *= 26;
        }
        return n;
    }