excel-sheet-column-number

Excel Sheet Column Number – LeetCode 171

Problem

Description

Given a column title as appear in an Excel sheet, return its corresponding column number.

Example

A -> 1
B -> 2
C -> 3
…
Z -> 26
AA -> 27
AB -> 28

Answer

Original

Code

class Solution {
public:
    int titleToNumber(string s) {
        unsigned sum = 0;
        for(char &c: s){
            sum *= 26;
            sum += c - 'A' + 1;
        }
        return sum;
    }
};

思路

没什么思路，水题。时间复杂度$O(n)$，空间复杂度$O(1)$。
耗时$6$ ms，排名$90.91\%$

Better

思路

没有看到更好的思路。