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# 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

```java
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;
    }
}
```