https://leetcode.com/problems/excel-sheet-column-number/
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
...
Example 1:
Input: "A" Output: 1
Example 2:
Input: "AB" Output: 28
Example 3:
Input: "ZY" Output: 701
代码：
class Solution {
public:
int titleToNumber(string s) {
int n = s.size();
int ans = 0;
int tmp = 1;
for (int i = n; i >= 1; --i) {
ans += (s[i - 1] - 'A' + 1) * tmp;
tmp *= 26;
}
return ans;
}
};
二十六进制转十进制