Excel Sheet Column Number

Problem

Given a string columnTitle that represents the 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: columnTitle = "A"
Output: 1

Example 2:

Input: columnTitle = "AB"
Output: 28

Example 3:

Input: columnTitle = "ZY"
Output: 701

Constraints:

1 <= columnTitle.length <= 7
columnTitle consists only of uppercase English letters.
columnTitle is in the range ["A", "FXSHRXW"].

Solution

/**
 * @param {string} s
 * @return {number}
 */
var titleToNumber = function(s) {
    let val = 0;
    let digit = s.length - 1;
    for (let c of s) {
        val += (c.charCodeAt(0) - 64) * 26 ** digit;
        digit--;
    }
    return val;
};

Convert base 26 value to base 10 value.

Problem​

Solution​

Problem

Solution