230408 단체사진 찍기

static String[] people;
static HashMap<Character, Integer> map;
static boolean[] visited;
static int[] positions;
static int count;

public static int solution(int n, String[] data) {
    if (data.length != n) {
        return 0;
    }
    people = data;
    map = new HashMap<>();
    visited = new boolean[8];
    positions = new int[8];
    count = 0;
    map.put('A', 0);
    map.put('C', 1);
    map.put('F', 2);
    map.put('J', 3);
    map.put('M', 4);
    map.put('N', 5);
    map.put('R', 6);
    map.put('T', 7);
    dfs(0);
    return count;
}

public static void dfs(int idx) {
    if (idx == 8) {
        if (isValidArrangement()) {
            count++;
        }
    } else {
        for (int i = 0; i < 8; i++) {
            if (!visited[i]) {
                visited[i] = true;
                positions[idx] = i;
                dfs(idx + 1);
                visited[i] = false;
            }
        }
    }
}

public static boolean isValidArrangement() {
    for (String condition : people) {
        int pos1 = positions[map.get(condition.charAt(0))];
        int pos2 = positions[map.get(condition.charAt(2))];
        int distance = condition.charAt(4) - '0' + 1;
        char operator = condition.charAt(3);

        switch (operator) {
            case '=':
                if (Math.abs(pos1 - pos2) != distance) {
                    return false;
                }
                break;
            case '>':
                if (Math.abs(pos1 - pos2) <= distance) {
                    return false;
                }
                break;
            case '<':
                if (Math.abs(pos1 - pos2) >= distance) {
                    return false;
                }
                break;
            default:
                break;
        }
    }
    return true;
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/1835