LeetCode in Kotlin
2544. Alternating Digit Sum
Easy
You are given a positive integer n. Each digit of n has a sign according to the following rules:
- The most significant digit is assigned a positive sign.
- Each other digit has an opposite sign to its adjacent digits.
Return the sum of all digits with their corresponding sign.
Example 1:
Input: n = 521
Output: 4
Explanation: (+5) + (-2) + (+1) = 4.
Example 2:
Input: n = 111
Output: 1
Explanation: (+1) + (-1) + (+1) = 1.
Example 3:
Input: n = 886996
Output: 0
Explanation: (+8) + (-8) + (+6) + (-9) + (+9) + (-6) = 0.
Constraints:
1 <= n <= 109
Solution
class Solution {
fun alternateDigitSum(n: Int): Int {
val s = Integer.toString(n)
val arr = s.toCharArray()
var res = 0
for (i in arr.indices) {
res += Math.pow(-1.0, i.toDouble()).toInt() * (arr[i].code - '0'.code)
}
return res
}
}