Sudoku.java

import java.util.Scanner;
import java.util.ArrayList;

/**
 * Created by Wook on 2015-12-29.
 */
public class Sudoku{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList<Integer> arrList = new ArrayList<>();

        System.out.print("원하는 크기를 입력하세요 : ");
        int size = sc.nextInt();

        int[] arrSudoku = new int[size];
        for (int i = 1; i <= size; i++)
            arrSudoku[i - 1] = i;

        sudoku(arrSudoku, size, 0, arrList);
        sudokuPrint(arrList, size);
    }


    public static void sudoku(int[] arr, int size, int pStart, ArrayList<Integer> arrList) {
        if (pStart == size) { // 한번 pStart 가 k로 도달하면 반복문 끝.
            for (int i = 0; i < size; i++) {
                arrList.add(arr[i]);
            }
//                System.out.print(arrList);
//                arrList.clear();
//                System.out.println();
//                System.out.println(count);
        }
        for (int i = pStart; i < size; i++) {
            swap(arr, i, pStart);
            sudoku(arr, size, pStart + 1, arrList);
            //sudoku(arr, size, pStart+1, arrList, count+1);
            //swap(arr, i, pStart);
        }
   //     System.out.println(pStart);
    }

    // swap함수. 임의의 공간 temp를 만들고 이를 통해 인덱스 i와 j의 값을 교환.
    public static void swap(int[] arr, int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }

    public static void sudokuPrint(ArrayList<Integer> arrList, int size) {
//        System.out.println(arrList);
//        Random random = new Random();
//        int cloneNum = 0;
        int count = 0;
        while (count != size * size) {
//                int ranNum = random.nextInt(arrList.size());
//                if(cloneNum != ranNum) {
            System.out.print("[" + arrList.get(count) + "]\t");
//                }
//                cloneNum = ranNum;
//                arrList.remove(count);
            count++;

            if (count % size == 0)
                System.out.println();
        }
    }
}