Excel Column Number

Posted: 25 Jul, 2020
Difficulty: Easy

PROBLEM STATEMENT

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You have been given a column title as appears in an Excel sheet, return its corresponding column number.

For example:
A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28 
...
Input Format
The only line of input contains a string S i.e. column title 
Constraints:
1 <= |S| <= 10
Input contains only uppercase English Alphabet letters

Time Limit : 1 sec
Output Format
The only line of output will print the column number corresponding to given column title 
Approach 1

The process is very much similar to binary to decimal conversion. In this case, the base of the given system is to be taken as 26. Also, in this system 1 is represented as ‘A’, 2 is represented as ‘B’ and so on till 26 is represented as ‘Z’



For example- 

 

CDA can be converted as 3*26*26 + 4*26 + 1

                                          = 26(3*26 + 4) + 1

                                          = 26(0*26 + 3*26 + 4) + 1

 

AB can be converted as  1*26 + 2

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