Related to question Excel Sheet Column Title
Given a column title as appear in an Excel sheet, return its corresponding column number.
For example:
代码语言：javascript复制 A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28 字符串转数字
类似于进制转换，可以理解为26进制转10进制
代码语言：javascript复制class Solution {
public:
int titleToNumber(string s) {
int res = 0 , base = 1;
for(int i = s.size()-1; i >= 0; i--)
{
res = base*(s[i] 1-'A');
base*=26;
}
return res;
}
};
