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
Credits: Special thanks to @ts for adding this problem and creating all test cases.
进制转化，比如2进制转化成10进制
int titleToNumber(char* s)
{
if (s == NULL)
return 0;
int result = 0;
while (*s) {
result *= 26;
result += *s - 'A' + 1;
s++;
}
return result;
}