백준 17299번 오등큰수 [ Java ]

17299번: 오등큰수

오큰수랑 똑같은 방식에 빈도 비교하는 배열만 추가하였습니다.

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        Stack<Integer> stack = new Stack<>();
        StringBuilder sb = new StringBuilder();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());

        int N = Integer.parseInt(st.nextToken());
        int res[] = new int[N];
        int freq[] = new int[1000001];
        int num[] = Arrays.stream(br.readLine().split(" "))
                .mapToInt(Integer::parseInt)
                .toArray();

        for (int i : num) freq[i]++;
        for (int i = 0; i < N; i++) {
            if (stack.isEmpty())
                stack.push(i);
            while (!stack.isEmpty() && freq[num[stack.peek()]] < freq[num[i]])
                res[stack.pop()] = num[i];
            stack.push(i);
        }
        while (!stack.isEmpty())
            res[stack.pop()] = -1;
        for (int i : res)
            sb.append(i + " ");
        System.out.print(sb);
    }
}