[leetcode]C语言: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

int titleToNumber(char *s) {
int sum = 0;
int tmp = 0;
int k=1;
while (*(s+k)){
k++;
}
for (int i = 0; i < k; ++i) {
tmp = s[i] - 'A' + 1;
sum = 26 * sum + tmp;
}
return sum;
}