LeetCode in Kotlin
171. Excel Sheet Column Number
Easy
Given a string columnTitle that represents the 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 …
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 <= 7columnTitleconsists only of uppercase English letters.columnTitleis in the range["A", "FXSHRXW"].
Solution
class Solution {
fun titleToNumber(s: String): Int {
var num = 0
var pow = 0
for (i in s.length - 1 downTo 0) {
num += Math.pow(26.0, pow++.toDouble()).toInt() * (s[i].code - 'A'.code + 1)
}
return num
}
}