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



Credits:
Special thanks to ​​​@ts​​ for adding this problem and creating all test cases.


思路：
26进制问题，从后向前遍历字符串

Java代码如下：

public class Solution
    public int titleToNumber(String s) {
        if("".equals(s)) {
            return 0;
        }
        int carry = 1, sum = 0;
        int len = s.length();
        for(int i = len - 1; i >= 0; i--) {
            int d = s.charAt(i) - 'A' + 1;
            d *= carry; 
            sum += d;
            carry *= 26;            
        }
        return

今天就到这里吧， 拜拜~