171.leetcode Excel Sheet Column Number(easy)[进制转换]

Related to question Excel Sheet Column Title

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

题目的含义是将A这样表示的转换成十进制，其实就是每逢26进制转换一次

class Solution {
public:
int titleToNumber(string s) {
int result = 0;
for(int i=0;i<s.length();i++)
{
result += (s[i]-'A'+1)*pow(26,s.length()-1-i);
}
return result;
}
};