【leetcode】171. Excel Sheet Column Number

一、题目描述

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 

c++代码（8ms）

思路：先找规律，找到规律后很容易就能写出代码

#include
#include
#include

看了一下discuss，大神的代码如下：

java

int result = 0;
for (int i = 0; i < s.length(); result = result * 26 + (s.charAt(i) - 'A' + 1), i++);
return result;

c++

int result = 0;
for (int i = 0; i < s.size(); result = result * 26 + (s.at(i) - 'A' + 1), i++);
return result;

python

return reduce(lambda x, y : x * 26 + y, [ord(c) - 64 for c in list(s)])