Excel Sheet Column Number

Description

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 
    ...

Example 1:

Input: "A"
Output: 1

Example 2:

Input: "AB"
Output: 28

Example 3:

Input: "ZY"
Output: 701

 

Constraints:

• 1 <= s.length <= 7
• s consists only of uppercase English letters.
• s is between "A" and "FXSHRXW".

Solution(javascript)

const titleToNumber = (s = '') => {
  let result = 0
  for (let i = s.length - 1; i >= 0; i--) {
    result += (s[i].charCodeAt(0) - 'A'.charCodeAt(0) + 1) * (26 ** (s.length - 1 - i))
  }
  return result
}