Excel Sheet Column Number 进制转换

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 

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

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