class Solution {
public:
int titleToNumber(string s) {
int ans=0;
for(int i=0;i<s.length();i++)
{
ans*=26;
ans+=s[i]-'A'+1;
}
return ans;
}
};LeetCode 171. Excel Sheet Column Number
原文：https://www.cnblogs.com/dacc123/p/12236094.html