LeetCode in Kotlin
3471. Find the Largest Almost Missing Integer
Easy
You are given an integer array nums and an integer k.
An integer x is almost missing from nums if x appears in exactly one subarray of size k within nums.
Return the largest almost missing integer from nums. If no such integer exists, return -1.
A subarray is a contiguous sequence of elements within an array.
Example 1:
Input: nums = [3,9,2,1,7], k = 3
Output: 7
Explanation:
- 1 appears in 2 subarrays of size 3:
[9, 2, 1]and[2, 1, 7]. - 2 appears in 3 subarrays of size 3:
[3, 9, 2],[9, 2, 1],[2, 1, 7]. - 3 appears in 1 subarray of size 3:
[3, 9, 2]. - 7 appears in 1 subarray of size 3:
[2, 1, 7]. - 9 appears in 2 subarrays of size 3:
[3, 9, 2], and[9, 2, 1].
We return 7 since it is the largest integer that appears in exactly one subarray of size k.
Example 2:
Input: nums = [3,9,7,2,1,7], k = 4
Output: 3
Explanation:
- 1 appears in 2 subarrays of size 4:
[9, 7, 2, 1],[7, 2, 1, 7]. - 2 appears in 3 subarrays of size 4:
[3, 9, 7, 2],[9, 7, 2, 1],[7, 2, 1, 7]. - 3 appears in 1 subarray of size 4:
[3, 9, 7, 2]. - 7 appears in 3 subarrays of size 4:
[3, 9, 7, 2],[9, 7, 2, 1],[7, 2, 1, 7]. - 9 appears in 2 subarrays of size 4:
[3, 9, 7, 2],[9, 7, 2, 1].
We return 3 since it is the largest and only integer that appears in exactly one subarray of size k.
Example 3:
Input: nums = [0,0], k = 1
Output: -1
Explanation:
There is no integer that appears in only one subarray of size 1.
Constraints:
1 <= nums.length <= 500 <= nums[i] <= 501 <= k <= nums.length
Solution
class Solution {
fun largestInteger(nums: IntArray, k: Int): Int {
val freq = IntArray(51)
for (i in 0..nums.size - k) {
val set: MutableSet<Int> = HashSet<Int>()
for (j in i..<i + k) {
set.add(nums[j])
}
for (key in set) {
freq[key]++
}
}
for (i in 50 downTo 0) {
if (freq[i] == 1) {
return i
}
}
return -1
}
}