1021 회전하는 큐 JAVA

 

 

https://www.acmicpc.net/problem/1021

 

 

 

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

public class Q1021 {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");

        int n = Integer.parseInt(st.nextToken()), m = Integer.parseInt(st.nextToken());

        Deque<Integer> deque = new LinkedList<>();
        int[] index = new int[m];

        for(int i = 0; i < n; i++)
            deque.offer(i+1);

        st = new StringTokenizer(br.readLine(), " ");
        for(int i = 0; i < m; i++)
            index[i] = Integer.parseInt(st.nextToken());

        int i = 0, count = 0, result = 0;
        while(true) {
            if (i == m) break;

            if (index[i] == deque.peekFirst()) {
                deque.pollFirst();
                i++;
            } else {
                Iterator<Integer> it = deque.iterator();
                while (it.hasNext()) {
                    int tmp = it.next();
                    if (tmp == index[i]) break;
                    count++;
                }
                if (count < deque.size() - count) {
                    while (deque.peekFirst() != index[i]) {
                        deque.offerLast(deque.pollFirst());
                        result++;
                    }
                } else {
                    while (deque.peekFirst() != index[i]) {
                        deque.offerFirst(deque.pollLast());
                        result++;
                    }
                }
                count = 0;
            }
        }
        System.out.println(result);
    }
}