LeetCode 171. Excel Sheet Column Number(进制转换)

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 

思路：

26进制转换为10进制。

Code：

class Solution {public:    int titleToNumber(string s) {        int ans=0;        int len=s.size();        for(int i=len;i>0;i--){            ans+=(s[i-1]-'A'+1)*pow(26,len-i);                }        return ans;    }};