코딩테스트 연습 스택/큐 프린터

gistfile1.txt

package kr.eungi.test;

import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

import static org.junit.Assert.assertEquals;
// https://programmers.co.kr/learn/courses/30/lessons/42587?language=java#
/**
 * Example local unit test, which will execute on the development machine (host).
 *
 * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
 */
public class ExampleUnitTest {
    @Test
    public void addition_isCorrect() {
        assertEquals(1, solution(new int[]{2, 1, 3, 2}, 2));
        assertEquals(5, solution(new int[]{1, 1, 9, 1, 1, 1}, 0));
        assertEquals(9, solution(new int[]{1,2,3,4,5,6,7,8,9}, 0));
        assertEquals(8, solution(new int[]{3, 4, 1, 5, 6, 8, 9, 5, 4, 6, 7, 8}, 7));
        assertEquals(16, solution(new int[]{1,1,2,2,4,4,8,7,5,1,2,3,9,9,9,8,7,7,3,4,1,9,5}, 18));
    }

    public int solution(int[] priorities, int location) {
        int popCount = 0;
        int vLocation = location;

        Map<Integer,Integer> priorityCountMap = makePriorityCountMap(priorities);


        while (vLocation >= popCount) {
            if (haveMoreImportant(priorityCountMap, priorities[popCount])) {
                replaceEnd(priorities, popCount);
                vLocation--;
                if (vLocation < popCount) {
                    vLocation = priorities.length - 1;
                }
            } else {
                int popPriority = priorityCountMap.getOrDefault(priorities[popCount], 0);
                if (popPriority == 1) {
                    priorityCountMap.remove(priorities[popCount]);
                } else {
                    priorityCountMap.put(priorities[popCount], popPriority - 1);
                }
                popCount++;
            }
        }

        return popCount;

    }

    public boolean haveMoreImportant(Map<Integer,Integer> map, int priority) {
        for (Integer integer : map.keySet()) {
            if (integer > priority) return true;
        }
        return false;
    }

    public void replaceEnd(int[] array, int from) {
        int temp = array[from];
        for (int i = from; i < array.length - 1; i++) {
            array[i] = array[i+1];
            array[i+1] = temp;
        }
    }

    public HashMap<Integer,Integer> makePriorityCountMap(int[] priorities) {
        HashMap<Integer,Integer> priorityMap = new HashMap<>();
        for (int p : priorities) {
            int count = priorityMap.getOrDefault(p, 0);
            priorityMap.put(p, count + 1);
        }
        return priorityMap;
    }
}