private static final int MISS_RUN_TIME = 5;
public int solution(int cacheSize, String[] cities) {
    if (cacheSize == 0) {
        return cities.length * MISS_RUN_TIME;
    }

    Map<String, Integer> lru = new LinkedHashMap<String, Integer>(cacheSize, 1, true){
        @Override
        public boolean removeEldestEntry(Map.Entry<String, Integer> eldest) {
            return size() > cacheSize;
        }
    };

    int answer = 0;
    for(String key : cities) {
        key = key.toLowerCase();

        if(lru.containsKey(key)) {
            lru.get(key);
            answer += 1;
        } else {
            lru.put(key, 0);
            answer += MISS_RUN_TIME;
        }
    }

    return answer;
}

assertEquals(42, test.solution(3, new String[]{"Jeju", "Pangyo", "Jeju", "NewYork", "LA", "Jeju", "Pangyo", "Seoul", "NewYork", "LA"}));
assertEquals(50, test.solution(3, new String[]{"Jeju", "Pangyo", "Seoul", "NewYork", "LA", "Jeju", "Pangyo", "Seoul", "NewYork", "LA"}));
assertEquals(21, test.solution(3, new String[]{"Jeju", "Pangyo", "Seoul", "Jeju", "Pangyo", "Seoul", "Jeju", "Pangyo", "Seoul"}));
assertEquals(60, test.solution(2, new String[]{"Jeju", "Pangyo", "Seoul", "NewYork", "LA", "SanFrancisco", "Seoul", "Rome", "Paris", "Jeju", "NewYork", "Rome"}));
assertEquals(52, test.solution(5, new String[]{"Jeju", "Pangyo", "Seoul", "NewYork", "LA", "SanFrancisco", "Seoul", "Rome", "Paris", "Jeju", "NewYork", "Rome"}));
assertEquals(16, test.solution(2, new String[]{"Jeju", "Pangyo", "NewYork", "newyork"}));
assertEquals(25, test.solution(0, new String[]{"Jeju", "Pangyo", "Seoul", "NewYork", "LA"}));
assertEquals(18, test.solution(1, new String[]{"LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA", "LA"}));

public int[] solution(int brown, int yellow) {
    int sum = brown + yellow;
    int[] answer = new int[2];

    for (int i = 2; i < sum; i++) {
        if (sum % i == 0) {
            int x = ((sum / i) * 2) + ((i * 2) - 4);
            int y = sum - x;

            if (brown == x && yellow == y) {
                answer = new int[] {sum / i, i};
                break;
            }
        }
    }
    return answer;
}

assertArrayEquals(new int[]{4, 3}, test.solution(10, 2));
assertArrayEquals(new int[]{3, 3}, test.solution(8, 1));
assertArrayEquals(new int[]{8, 6}, test.solution(24, 24));

private static final String ENTER = "Enter";
private static final String LEAVE = "Leave";
private static final String CHANGE = "Change";

private static final String MESSAGE_ENTER = "님이 들어왔습니다.";
private static final String MESSAGE_LEAVE = "님이 나갔습니다.";

public String[] solution(String[] record) {
    List<String[]> list = new ArrayList<>();
    Map<String, String> nickName = new HashMap<>();

    int returnArraySize = 0;
    for (String s : record) {
        String[] split = s.split(" ");
        String[] actionAndUid = new String[3];

        actionAndUid[0] = split[0];
        actionAndUid[1] = split[1];

        if (!CHANGE.equals(split[0])) {
            list.add(actionAndUid);
            returnArraySize++;
        }

        if (!LEAVE.equals(split[0])) {
            nickName.put(split[1], split[2]);
        }
    }

    String[] answer = new String[returnArraySize];
    int i = 0;
    for (String[] array : list) {
        switch (array[0]) {
            case ENTER :
                answer[i] = nickName.get(array[1]) + MESSAGE_ENTER;
                break;
            case LEAVE :
                answer[i] = nickName.get(array[1]) + MESSAGE_LEAVE;
                break;
        }

        i++;
    }

    return answer;
}

String[] actual = {"Enter uid1234 Muzi", "Enter uid4567 Prodo","Leave uid1234","Enter uid1234 Prodo","Change uid4567 Ryan"};
String[] expected ={"Prodo님이 들어왔습니다.", "Ryan님이 들어왔습니다.", "Prodo님이 나갔습니다.", "Prodo님이 들어왔습니다."};
assertArrayEquals(expected, test.solution(actual));

public int[][] solution(int[][] arr1, int[][] arr2) {
    int[][] answer = new int[arr1.length][arr2[0].length];

    for (int i = 0; i < arr1.length; i++) {
        for(int j = 0; j < arr2[0].length; j++){
            for (int k = 0; k < arr2.length; k++) {
                answer[i][j] += arr1[i][k] * arr2[k][j];
            }
        }
    }

    return answer;
}

assertArrayEquals(new int[][] {{15, 15}, {15, 15}, {15, 15}}, test.solution(new int[][] {{1, 4}, {3, 2}, {4, 1}}, new int[][] {{3, 3}, {3, 3}}));
assertArrayEquals(new int[][] {{22, 22, 11}, {36, 28, 18}, {29, 20, 14}}, test.solution(new int[][] {{2, 3, 2}, {4, 2, 4}, {3, 1, 4}}, new int[][] {{5, 4, 3}, {2, 4, 1}, {3, 1, 1}}));

int solution(int[][] land) {
    for (int i = land.length - 2; i >= 0; i--) {
        int rowIndex = i + 1;
        land[i][0] += max(land[rowIndex][1], max(land[rowIndex][2], land[rowIndex][3]));
        land[i][1] += max(land[rowIndex][0], max(land[rowIndex][2], land[rowIndex][3]));
        land[i][2] += max(land[rowIndex][0], max(land[rowIndex][1], land[rowIndex][3]));
        land[i][3] += max(land[rowIndex][0], max(land[rowIndex][1], land[rowIndex][2]));
    }

    int answer = max(land[0][0], max(land[0][1], max(land[0][2], land[0][3])));
    return answer;
}

assertEquals(16, test.solution(new int[][] {{1,2,3,5},{5,6,7,8},{4,3,2,1}}));
assertEquals(20, test.solution(new int[][] {{4, 3, 2, 1}, {2, 2, 2, 1}, {6, 6, 6, 4}, {8, 7, 6, 5}}));
assertEquals(115, test.solution(new int[][] {{1, 2, 3, 5}, {5, 6, 7, 8}, {4, 3, 2, 1}, {100, 0, 9, 8}}));
assertEquals(33, test.solution(new int[][] {{1, 2, 3, 5}, {10, 11, 12, 11}, {16, 15, 13, 13}}));
assertEquals(409, test.solution(new int[][] {{1, 100, 15, 3}, {1, 2, 3, 4}, {100, 99, 98, 97}, {97, 98, 99, 100}, {4, 3, 2, 1}, {100, 100, 100, 100}, {1, 1, 1, 1}}));
assertEquals(16, test.solution(new int[][] {{1, 2, 3, 4}, {5, 6, 7, 9}, {4, 3, 2, 1}}));
assertEquals(125, test.solution(new int[][] {{9, 5, 2, 3}, {9, 8, 6, 7}, {8, 9, 7, 1}, {100, 9, 8, 1}}));
assertEquals(20, test.solution(new int[][] {{4, 3, 2, 1}, {2, 2, 2, 1}, {6, 6, 6, 4}, {8, 7, 6, 5}}));

private static final char PLUS = '+';
private static final char MINUS = '-';
private static final char MULTIPLICATION = '*';

public long solution(String expression) {
    char[] chars = expression.toCharArray();

    Object[] numberAndOperator = getNumbersAndOperatorSet(chars);
    List<Long> numberList = (List<Long>) numberAndOperator[0];
    List<Character> operatorList = (List<Character>) numberAndOperator[1];

    char[] operators = getExpressionIncludeOperators(operatorList);
    List<String> operatorSetList = getOperatorSetList(operators);

    return getMax(numberList, operatorList, operatorSetList);
}

private Object[] getNumbersAndOperatorSet(char[] expression) {
    List<Long> numberList = new ArrayList<>();
    List<Character> operatorList = new ArrayList<>();

    StringBuilder sb = new StringBuilder();
    for (char c : expression) {
        switch (c) {
            case PLUS:
            case MINUS:
            case MULTIPLICATION:
                numberList.add(Long.valueOf(sb.toString()));
                operatorList.add(c);

                sb.setLength(0);
                break;
            default:
                sb.append(c);
                break;
        }
    }

    numberList.add(Long.valueOf(sb.toString()));

    return new Object[] {numberList, operatorList};
}

private char[] getExpressionIncludeOperators(List<Character> operatorList) {
    Set<Character> set = new HashSet<>();
    List<Character> list = new ArrayList<>();

    for (char c : operatorList) {
        if (set.add(c)) {
            list.add(c);
        }
    }

    char[] operators = new char[list.size()];
    int i = 0;
    for (char c : list) {
        operators[i++] = c;
    }

    return operators;
}


private List<String> getOperatorSetList(char[] chars) {
    List<String> operatorSetList = new ArrayList<>();
    Set<String> set = new HashSet<>();

    for (int i = 1; i <= chars.length; i++) {
        perm(chars, 0, i, operatorSetList, set);
    }

    return operatorSetList;
}

private void perm(char[] array, int depth, int length, List<String> operatorList, Set<String> set) {
    if (depth == length) {

        StringBuilder sb = new StringBuilder();
        for (char c : array) {
            sb.append(c);
        }

        if (set.add(sb.toString())) {
            operatorList.add(sb.toString());
        }

        return;
    }

    for (int i = depth; i < array.length; i++) {
        swap(array, i, depth);
        perm(array, depth + 1, length, operatorList, set);
        swap(array, i, depth);
    }
}

private void swap(char[] arrary, int i, int j) {
    char temp = arrary[i];
    arrary[i] = arrary[j];
    arrary[j] = temp;
}

private Long getMax(List<Long> numberList, List<Character> operatorList, List<String> operatorSetList) {
    long max = 0;

    for (String operatorSet : operatorSetList) {
        char[] operators = operatorSet.toCharArray();

        LinkedList<Long> numberQueue = new LinkedList<>(numberList);
        LinkedList<Character> operatorQueue = new LinkedList<>(operatorList);

        for (char operatorToCalculate : operators) {
            Stack<Long> numberStack = new Stack<>();
            Stack<Character> operatorStack = new Stack<>();

            long first = numberQueue.poll();
            numberStack.push(first);
            numberQueue.offer(first);

            Stack[] stacks = new Stack[] {numberStack, operatorStack};
            LinkedList[] queues = new LinkedList[] {numberQueue, operatorQueue};

            calculatePriority(stacks, queues, operatorToCalculate);
        }

        max = (max > Math.abs(numberQueue.peek())) ? max : Math.abs(numberQueue.poll());
    }

    return max;
}

private void calculatePriority(Stack[] staks, LinkedList[] queues, char operatorToCalculate) {
    Stack<Long> numberStack = staks[0];
    Stack<Character> operatorStack = staks[1];

    LinkedList<Long> numberQueue = queues[0];
    LinkedList<Character> operatorQueue = queues[1];

    int limit = operatorQueue.size();
    for (int i = 0; i < limit; i++) {
        long currentNumber = numberQueue.poll();
        numberStack.push(currentNumber);

        Character currentOperator = operatorQueue.poll();
        operatorStack.push(currentOperator);

        if (operatorStack.peek() == operatorToCalculate) {
            long n1 = numberStack.pop();
            long n2 = numberStack.pop();
            char op = operatorStack.pop();

            long sum = sum(n2, n1, op);
            numberStack.push(sum);

            numberQueue.pollLast();
            numberQueue.offer(sum);
        } else {
            numberQueue.offer(currentNumber);
            operatorQueue.offer(currentOperator);
        }
    }
}

private Long sum(long n2, long n1, char op) {
    long sum = 0;

    switch (op) {
        case '*' :
            sum = n2 * n1;
            break;
        case '+' :
            sum = n2 + n1;
            break;
        case '-' :
            sum = n2 - n1;
            break;
    }

    return sum;
}

LinkedList<Long> numberQueue = new LinkedList<>(numberList);
LinkedList<Character> operatorQueue = new LinkedList<>(operatorList);

long first = numberQueue.poll();
numberStack.push(first);
numberQueue.offer(first);

for (int i = 0; i < limit; i++) {
    long currentNumber = numberQueue.poll();
    numberStack.push(currentNumber);

    Character currentOperator = operatorQueue.poll();
    operatorStack.push(currentOperator);

    if (operatorStack.peek() == operatorToCalculate) {
        long n1 = numberStack.pop();
        long n2 = numberStack.pop();
        char op = operatorStack.pop();

        long sum = sum(n2, n1, op);
        numberStack.push(sum);

        numberQueue.pollLast();
        numberQueue.offer(sum);
    } else {
        numberQueue.offer(currentNumber);
        operatorQueue.offer(currentOperator);
    }
}

assertEquals(60420, test.solution("100-200*300-500+20"));
assertEquals(300, test.solution("50*6-3*2"));

@ExtendWith(SpringExtension.class)
@DataJpaTest
@TestPropertySource("classpath:application-test.properties")
class WordRepositoryTest {
    ...
}

@BeforeEach
void setUp() {
    user = new User();
    user.setUsername("jgji");
    user.setPassword("qwe123");

    userRepository.save(this.user);

    user1 = new User();
    user.setUsername("haha");
    user.setPassword("qwe123");

    userRepository.save(this.user1);

    List<Word> givenWordList = getWordGiven();
    this.word = givenWordList.get(0);
    this.word1 = givenWordList.get(1);
}