ExcelSheetColumnNumber171.kt

package easy

/**
 * 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"].
 */

fun titleToNumber(columnTitle: String): Int {

    var result =0

    columnTitle.forEachIndexed { index, char ->
        if(index!=0)
            result*=26
        result+=(char-'A')+1
    }
    return result

}