[JAVA]実装シーケンス、繰り返しシーケンス、組合せおよび繰り返し組合せ

import java.util.Arrays;

public class permutation {

	static int arr[]; 
	static boolean isSelected[];
	static int numbers[];
	static int n = 5;
	static int r = 5;
	
	public static void main(String[] args) {
		arr= new int[]{1,2,3,4,5};
		isSelected = new boolean[r];
		numbers = new int[r];
		
		per(0);
	}
	
	public static void per(int cnt) {
		if(cnt==r) {
			System.out.println(Arrays.toString(numbers));
			return;
		}
		
		for(int i=0;i<n;i++) {
			if(isSelected[i])continue;
			numbers[cnt] = arr[i];
			isSelected[i] = true;
			per(cnt+1);
			isSelected[i] = false;
		}
	}

}

import java.util.Arrays;

public class PermutationWithRepetition {

	static int arr[];
	static int numbers[];
	static int n = 5;
	static int r = 3;
	public static void main(String[] args) {
		
		arr = new int[] {1,2,3,4,5};
		numbers = new int[r];
		
		perRep(0);
	}
	
	public static void perRep(int cnt) {
		if(cnt == r) {
			System.out.println(Arrays.toString(numbers));
			return;
		}
		
		for(int i=0;i<n;i++) {
			numbers[cnt] = arr[i];
			perRep(cnt+1);
		}
	}

}

import java.util.Arrays;

public class Combination {

	static int arr[];
	static int numbers[];
	static int n = 5;
	static int r = 3;
	public static void main(String[] args) {
		
		arr = new int[] {1,2,3,4,5};
		numbers = new int[r];
		
		combi(0,0);
	}

	
	public static void combi(int start, int cnt) {
		if(cnt == r) {
			System.out.println(Arrays.toString(numbers));
			return;
		}
		
		for(int i=start;i<n;i++) {
			numbers[cnt] = arr[i];
			combi(i+1,cnt+1);
		}
	}
}

import java.util.Arrays;

public class CombinationWithRepetition {

	static int arr[];
	static int numbers[];
	static int n = 3;
	static int r = 4;
	public static void main(String[] args) {

		arr = new int[] {1,2,3};
		numbers = new int[r];
		
		comRep(0);
	}
	
	public static void comRep(int cnt) {
		if(cnt == r) {
			System.out.println(Arrays.toString(numbers));
			return;
		}
		
		for(int i=0;i<n;i++) {
			numbers[cnt] = arr[i];
			comRep(cnt+1);
		}
	}

}