文章作者：Tyan
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1. Description

Least Number of Unique Integers after K Removals

2. Solution

• Version 1

class Solution:
    def findLeastNumOfUniqueInts(self, arr, k):
        stat = {}
        for num in arr:
            stat[num] = stat.get(num, 0) + 1
        result = sorted(stat.items(), key=lambda item: item[1])
        while k > 0:
            k = k - result[0][1]
            if k >= 0:
                result.pop(0)
        return len(result)

• Version 2

class Solution:
    def findLeastNumOfUniqueInts(self, arr, k):
        stat = {}
        for num in arr:
            stat[num] = stat.get(num, 0) + 1
        result = sorted(stat.items(), key=lambda item: item[1])
        index = 0
        while k > 0:
            k = k - result[index][1]
            if k >= 0:
                index += 1
        return len(result) - index

• Version 3

class Solution:
    def findLeastNumOfUniqueInts(self, arr, k):
        stat = {}
        for num in arr:
            stat[num] = stat.get(num, 0) + 1
        result = sorted(arr, key=lambda num: (stat[num], num))
        return len(set(result[k:]))

Reference

1. https://leetcode.com/problems/least-number-of-unique-integers-after-k-removals/