1481. Least Number of Unique Integers after K Removal - Explanation

class Solution:
    def findLeastNumOfUniqueInts(self, arr: List[int], k: int) -> int:
        freq = sorted(Counter(arr).values())
        n = len(freq)
        for i in range(n):
            if k >= freq[i]:
                k -= freq[i]
            else:
                return n - i
        return 0

class Solution:
    def findLeastNumOfUniqueInts(self, arr: List[int], k: int) -> int:
        freq = Counter(arr)
        heap = list(freq.values())
        heapq.heapify(heap)

        res = len(heap)
        while k > 0 and heap:
            f = heapq.heappop(heap)
            if k >= f:
                k -= f
                res -= 1
        return res

class Solution:
    def findLeastNumOfUniqueInts(self, arr: List[int], k: int) -> int:
        freq = Counter(arr)
        freq_list = [0] * (len(arr) + 1)

        for n, f in freq.items():
            freq_list[f] += 1

        res = len(freq)
        for f in range(1, len(freq_list)):
            remove = freq_list[f]
            if k >= f * remove:
                k -= f * remove
                res -= remove
            else:
                remove = k // f
                res -= remove
                break
        return res