Math Number Theory Combinatorics
Learner Level

Implement the excelColumnNumber method that converts an Excel column title into its column number.

The input contains a string column representing an Excel column title. Your task is to convert it into its column number.

Excel columns work like a base-26 number system where A is 1, B is 2, and Z is 26. After Z, the next column is AA.

Example 1
Input:
column (string) = AB
Return:
(int) 28
Example 2
Input:
column (string) = A
Return:
(int) 1
Example 3
Input:
column (string) = ZY
Return:
(int) 701

Process the column title from left to right like a base-26 number.

For each character, multiply the current answer by 26 and add the character value. The value of a character is its position in the alphabet, where A = 1 and Z = 26.

For example, AB becomes 1 * 26 + 2 = 28.

Pseudocode:

function excelColumnNumber(column):
    result = 0
    for each character ch in column:
        value = position of ch from A to Z
        result = result * 26 + value
    return result
Run your code to see the result.