171.Excel-Sheet-Column-Number

171. Excel Sheet Column Number

题目地址

https://leetcode.com/problems/excel-sheet-column-number/

题目描述

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 
    ...
Example 1:

Input: "A"
Output: 1
Example 2:

Input: "AB"
Output: 28
Example 3:

Input: "ZY"
Output: 701

代码

Approach #1

class Solution {
    public int titleToNumber(String s) {
      int result = 0;
      for(int i = 0 ; i < s.length(); i++) {
        result = result * 26 + (s.charAt(i) - 'A' + 1);
      }
      return result;
    }
}