Excel Sheet Column Number

Excel Sheet Column Number

Total Accepted: 55771 Total Submissions: 142875 Difficulty: Easy

 

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 

相当于26进制，拿十进制做类比就可以了，相当于如何把字符串"1234"转整数1234

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

Next challenges: (E) Excel Sheet Column Title