[백준] 17299 오등큰수 - Data Structure / Java

• 문제 링크

17299번: 오등큰수

 

• 풀이 과정

 

• 풀이 코드

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Stack;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        int[] arr = new int[n];
        int[] cnt = new int[1000001];

        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            arr[i] = Integer.parseInt(st.nextToken());
            cnt[arr[i]]++;
        }

        Stack<Integer> stk = new Stack<>();
        for (int i = 0; i < n; i++) {
            while (!stk.empty() && cnt[arr[stk.peek()]] < cnt[arr[i]])
                arr[stk.pop()] = arr[i];

            stk.push(i);
        }

        while (!stk.empty())
            arr[stk.pop()] = -1;

        for (int i = 0; i < n; i++)
            bw.write(arr[i] + " ");

        bw.flush();
    }

}