Leetcode: Excel Sheet Column Number, leetcodesheet

Leetcode: Excel Sheet Column Number, leetcodesheet

I. Question

Returns the column number corresponding to a column title that appears in an Excel table.

For example:

A-> 1

B-> 2

C-> 3

...

Z-> 26

AA-> 27

AB-> 28

Ii. Analysis

The question is very clear. In fact, a careful analysis is very simple, that is, converting a string into a deformation of the integer (atoi ()-base on 26, and simpler.

 

class Solution {public:    int titleToNumber(string s) {        int sum = 0;        for(int i = 0; s[i] != '\0'; i++){            sum = sum *26 + (s[i] - 'A' + 1);        }        return sum;    }};

I just learned Python, but it's easy to see:

class Solution:    # @param s, a string    # @return an integer    def titleToNumber(self, s):        sum = 0        for i in s:            sum = sum * 26 + ord(i) -ord('A') + 1        return sum