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
思路:
这道题本质上是将26进制转换位10进制,我们只需要以为乘上相应的权值就行了。
class Solution {
public:
int titleToNumber(string s) {
int res = 0;
for (auto i : s) {
res = res * 26 + (i - 'A' + 1);
}
return res;
}
};