[알고리즘문제풀기] 최빈값 구하기

문제

내가 작성한 정답

class Solution {
    public int solution(int[] array) {
        int f = 0, max = 0,cnt=0;
        int[] arr = new int[1000];
        for(int i:array) arr[i]++;
        for(int i=0; i<1000; i++){ 
            if(max<arr[i]) {f=i; max=arr[i];}
        }
        for(int i:arr) if(i==max) cnt++;
        return cnt>1?-1:f;
    }
}

다른 사람들의 정답

import java.util.*;
class Solution {
    public int solution(int[] array) {
        int maxCount = 0;
        int answer = 0;
        Map<Integer, Integer> map = new HashMap<>();
        for(int number : array){
            int count = map.getOrDefault(number, 0) + 1;
            if(count > maxCount){
                maxCount = count;
                answer = number;
            }
            else  if(count == maxCount){
                answer = -1;
            }
            map.put(number, count);
        }
        return answer;
    }
}

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.ArrayList;
import java.util.Arrays;

class Solution {
    public int solution(int[] array) {
        List<Map.Entry<Integer, List<Integer>>> list = new ArrayList<>(Arrays.stream(array).boxed().collect(Collectors.groupingBy(o -> o)).entrySet()).stream().sorted((t0, t1) -> Integer.compare(t1.getValue().size(), t0.getValue().size())).collect(Collectors.toList());
        return list.size() > 1 && list.get(0).getValue().size() - list.get(1).getValue().size() == 0 ? -1 : list.get(0).getKey();
    }
}