leetcode 171. Excel Sheet Column Number

171. Excel Sheet Column Number

Total Accepted: 66268 Total Submissions: 164127 Difficulty: Easy

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

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

Subscribe to see which companies asked this question

Hide Tags

Math

Show Similar Problems

 1 class Solution {
 2 public:
 3     int titleToNumber(string s) {
 4         string::reverse_iterator it;
 5         int ans = 0;
 6         int temp = 1;
 7         for(it = s.rbegin();it != s.rend(); it++){
 8             ans += ( (*it) - 'A' + 1 ) * temp;
 9             temp *= 26;
10         }
11         return ans;
12     }
13 };

转另外一个思路：

http://www.cnblogs.com/ganganloveu/p/4191180.html

 1 class Solution {
 2 public:
 3     int titleToNumber(string s) {
 4         int ans = 0;
 5         for(int i = 0;i < s.size();i++){
 6            ans*=26;
 7            ans += s[i] - 'A' + 1; 
 8         }
 9         return ans;
10     }
11 };