백준 17298 오큰수(JAVA)

문제 설명

https://www.acmicpc.net/problem/17298

 

풀이과정

 배열과 스택을 이용해서 풀이한다.

 

정답코드

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

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));

        int N = Integer.parseInt(br.readLine());

        int[] arr = new int[N];

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

        Stack<Integer> stack = new Stack<>();

        for (int i = 0; i < N; i++) {
            while (!stack.isEmpty() && arr[stack.peek()] < arr[i]) {
                arr[stack.pop()] = arr[i];
            }

            stack.push(i);
        }

        while (!stack.isEmpty()) {
            arr[stack.pop()] = -1;
        }

        for (int i : arr) {
            bw.write(i + " ");
        }

        bw.flush();
    }
}