[프로그래머스/그리디] Lv1. 키패드 누르기(자바)

클래스를 활용한 풀이

참고 : 개발자로 취직하기

class Solution {
    Position left;
    Position right;
    Position numPos;

    public String solution(int[] numbers, String hand) {
        String answer = "";
        // 1. 왼손 오른손 위치 초기화
        left = new Position(3, 0);
        right = new Position(3, 2);

        for (int num : numbers) {
            // 2. 숫자를 누를 손가락 정하기
            numPos = new Position((num - 1) / 3, (num - 1) % 3);
            if (num == 0)
                numPos = new Position(3, 1);
            String finger = numPos.getFinger(hand);

            // 3. 정해진 손가락을 answer에 담고, 손가락 위치 이동
            answer += finger;

            if (finger.equals("L"))
                left = numPos;
            else
                right = numPos;
        }

        return answer;
    }

    class Position {
        int row;
        int col;

        Position(int row, int col) {
            this.row = row;
            this.col = col;
        }

        public String getFinger(String hand) {
            String finger = hand.equals("right") ? "R" : "L";

            if (this.col == 0) finger = "L";
            else if (this.col == 2) finger = "R";
            else {
                int leftDist = left.getDistance(this);
                int rightDist = right.getDistance(this);

                if (leftDist < rightDist)
                    finger = "L";
                else if (rightDist < leftDist)
                    finger = "R";
            }

            return finger;
        }

        public int getDistance(Position p) {
            return Math.abs(this.row - p.row) + Math.abs(this.col - p.col);
        }
    }
}

 

내 풀이...

 

 

class Solution {
    String hand;
    String[] key = new String[]{"1","2","3","4","5","6","7","8","9","*","0","#"};
    String[][] keypad = new String[4][3];
    int[] currentLeft = new int[]{3,0}; // y,x (*)
    int[] currentRight = new int[]{3,2}; // y,x (#)

    public String solution(int[] numbers, String hand) {
        this.hand = hand;
        StringBuilder answer = new StringBuilder();

        // 1. 키패드 배열 초기화
        int num = 0;
        for(int i=0; i<4; i++) {
            for(int j=0; j<3; j++) {
                keypad[i][j] = key[num++];
            }
        }

        // 2. number 별 좌표 찾기
        for(int number : numbers) {
            int[] numberYX = findYXByNumber(number);

            if(numberYX[1] == 0) {
                // X 축이 0이면 왼손
                answer.append("L");
                currentLeft = numberYX;
            }
            // X 축이 2이면 오른손
            else if(numberYX[1]==2) {
                answer.append("R");
                currentRight = numberYX;
            }
            // X 축이 1이면 가까운 손
            else if (numberYX[1] == 1) {
                String closedHand = findHand(numberYX);
                if ("right".equals(closedHand)) {
                    answer.append("R");
                    currentRight = numberYX;
                } else if ("left".equals(closedHand)){
                    answer.append("L");
                    currentLeft = numberYX;
                }
            }
        }
        return answer.toString();
    }

    private int[] findYXByNumber(int number) {
        int[] result = new int[2];
        for (int i=0; i<4; i++) {
            for(int j=0; j<3; j++) {
                if(Integer.toString(number).equals(keypad[i][j])){
                    result = new int[]{i, j};
                }
            }
        }
        return result;
    }

    private String findHand(int[] position) {

        int right = Math.abs(position[1] - currentRight[1]) + Math.abs(position[0] - currentRight[0]);
        int left = Math.abs(position[1] - currentLeft[1]) + Math.abs(position[0] - currentLeft[0]);

        if(right < left) {
            return "right";
        } else if (left < right) {
            return "left";
        } else {
            return hand;
        }
    }

}