LeetCode in Kotlin

1481. Least Number of Unique Integers after K Removals

Medium

Given an array of integers arr and an integer k. Find the least number of unique integers after removing exactly k elements.

Example 1:

Input: arr = [5,5,4], k = 1

Output: 1

Explanation: Remove the single 4, only 5 is left.

Example 2:

Input: arr = [4,3,1,1,3,3,2], k = 3

Output: 2

Explanation: Remove 4, 2 and either one of the two 1s or three 3s. 1 and 3 will be left.

Constraints:

• 1 <= arr.length <= 10^5
• 1 <= arr[i] <= 10^9
• 0 <= k <= arr.length

Solution

@Suppress("NAME_SHADOWING")
class Solution {
    fun findLeastNumOfUniqueInts(arr: IntArray, k: Int): Int {
        var k = k
        val count: MutableMap<Int, Int> = HashMap()
        for (a in arr) {
            count[a] = 1 + count.getOrDefault(a, 0)
        }
        var remaining = count.size
        var occur = 1
        val occurrenceCount = IntArray(arr.size + 1)
        for (v in count.values) {
            ++occurrenceCount[v]
        }
        while (k > 0) {
            if (k - occur * occurrenceCount[occur] >= 0) {
                k -= occur * occurrenceCount[occur]
                remaining -= occurrenceCount[occur++]
            } else {
                return remaining - k / occur
            }
        }
        return remaining
    }
}

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