1.题目
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
2.解决方案
class Solution {
public:
int titleToNumber(string s) {
int sum = 0;
int tmp = 0;
for(int i = 0; i < s.size(); ++i){
sum = sum * 26 + s[i] - 'A' + 1;
}
return sum;
}
};
思路:26进制的概念。