LeetCode in Kotlin

3880. Minimum Absolute Difference Between Two Values

Easy

You are given an integer array nums consisting only of 0, 1, and 2.

A pair of indices (i, j) is called valid if nums[i] == 1 and nums[j] == 2.

Return the minimum absolute difference between i and j among all valid pairs. If no valid pair exists, return -1.

The absolute difference between indices i and j is defined as abs(i - j).

Example 1:

Input: nums = [1,0,0,2,0,1]

Output: 2

Explanation:

The valid pairs are:

Thus, the answer is 2.

Example 2:

Input: nums = [1,0,1,0]

Output: -1

Explanation:

There are no valid pairs in the array, thus the answer is -1.

Constraints:

Solution

import kotlin.math.min

class Solution {
    fun minAbsoluteDifference(nums: IntArray): Int {
        var min = Int.MAX_VALUE
        val n = nums.size
        var prev = -1
        var last = -1
        for (i in 0..<n) {
            if (prev == -1) {
                if (nums[i] == 1) {
                    prev = 1
                    last = i
                } else if (nums[i] == 2) {
                    prev = 2
                    last = i
                }
            } else {
                if (nums[i] == 1) {
                    if (prev == 2) {
                        min = min(min, i - last)
                        prev = 1
                    }
                    last = i
                } else if (nums[i] == 2) {
                    if (prev == 1) {
                        min = min(min, i - last)
                        prev = 2
                    }
                    last = i
                }
            }
        }
        return if (min != Int.MAX_VALUE) min else -1
    }
}