Java for LeetCode 171 Excel Sheet Column Number

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

解题思路：

JAVA实现如下：

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