LeetCode 171 Excel Sheet Column Number

题目描述

Related to question Excel Sheet Column Title

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

For example:

[code]A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28

Credits:

Special thanks to @ts for adding this problem and creating all test cases.

分析

相似题目：LeetCode 168 Excel Sheet Column Title

实质上就是26进制转成10进制。

代码

[code]    public static int titleToNumber(String s) {

        int n = 0;
        int p = 1;

        for (int i = s.length() - 1; i >= 0; i--) {
            n += (s.charAt(i) - 'A' + 1) * p;
            p *= 26;
        }

        return n;
    }