JUNGOL 1169 : 주사위 던지기1 (Java)(조합)(순열)

문제출처: jungol.co.kr/bbs/board.php?bo_table=pbank&wr_id=449&sca=2080

 

소스코드

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
 
public class 주사위던지기1_1169 {
 
    private static int N;
    private static int[] numbers;
    private static boolean[] visited;
    private static final int DICE = 6;
    private static final int START = 1;
    private static StringBuilder sb;
 
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        sb = new StringBuilder();
        String[] strArr = br.readLine().split(" ");
 
        N = Integer.parseInt(strArr[0]); // 주사위를 N번 던진다.
        int type = Integer.parseInt(strArr[1]); // 출력형태 결정자
        numbers = new int[N];
        visited = new boolean[DICE + 1];
        switch (type) {
        case 1:
            allSet(0); // 중복 가능 모두 출력
            break;
        case 2:
            dupCombination(0);
            break;
        case 3:
            permutation(0);
            break;
        case 4:
            combination(START, 0);
            break;
        default:
            break;
        }
        System.out.println(sb);
    }
 
    private static void allSet(int depth) {
        if (depth == N) {
            for (int i = 0; i < N; i++) {
                sb.append(numbers[i] + " ");
            }
            sb.append("\n");
            return;
        }
        for (int i = START; i <= DICE; i++) {
            numbers[depth] = i;
            allSet(depth + 1);
        }
 
    }
 
    private static void dupCombination(int depth) {
        if (depth == N) {
            for (int i = 0; i < N; i++) {
                sb.append(numbers[i] + " ");
            }
            sb.append("\n");
            return;
        }
        for (int i = START; i <= DICE; i++) {
            if (depth == 0 || numbers[depth - 1] <= i) {
                numbers[depth] = i;
                dupCombination(depth + 1);
            }
        }
    }
 
    private static void permutation(int depth) {
        if (depth == N) {
            for (int i = 0; i < N; i++) {
                sb.append(numbers[i] + " ");
            }
            sb.append("\n");
            return;
        }
        for (int i = START; i <= DICE; i++) {
            if (visited[i]) {
                continue;
            }
            numbers[depth] = i;
            visited[i] = true;
            permutation(depth + 1);
            visited[i] = false;
        }
    }
 
    private static void combination(int start, int depth) {
        if (depth == N) {
            for (int i = 0; i < N; i++) {
                sb.append(numbers[i] + " ");
            }
            sb.append("\n");
            return;
        }
        for (int i = start; i <= DICE; i++) {
            numbers[depth] = i;
            combination(start + 1, depth + 1);
        }
    }
 
}