java - 在二维数组中查找重复值

Question

我正在做的作业要求我在不使用任何类、方法、封装等的情况下创建一个数独游戏。我无法验证我的用户输入到我的“fourArray”或“nineArray”中的值不包含重复值。到目前为止，我一直在尝试使用嵌套的 for 循环来遍历任一数组的列和行。例如，我一直试图在我的程序末尾包含以下代码，以确定是否存在任何重复值:

for (int i = 0; i < fourArray.length; i++) {
    for (int j = i + 1; j < fourArray.length; j++)
        if (fourArray[i] == fourArray[j]) {
            System.out.println("No Sudoku");
        } else {
            System.out.println("Sudoku!);
        }
 }

但是这不起作用。我想遍历数组以找到任何重复的值，如果没有，则打印出“数独!”如果有任何重复值，那么我想打印出“数独!”我是否需要对数组进行排序？或者有什么我不知道的方法吗？我已经包含了我的程序。感谢您的宝贵时间。

import java.util.Scanner;


public class Sudoku {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int boardSize = -1;
        int[][] fourArray = { {0,0,0,0}, {0,0,0,0}, {0,0,0,0}, {0,0,0,0} };
        int[][] nineArray = { {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0} }; 
        while (true)
        {
            Scanner boardsizeOption = new Scanner(System.in);
            System.out.println("Please select a board size:" + "\n" + "1) 4x4" + "\n" + "2) 9x9");
            boardSize = boardsizeOption.nextInt();
            if (boardSize == 1 || boardSize == 2) {
                break;
            }
        }
        if (boardSize == 1) { //still need to build complete board 
            int i, j = 0;
            for (i = 0; i < fourArray.length; i++)
            {
                for (j = 0; j < fourArray.length; j++)
                    System.out.print(fourArray[i][j] + " ");
                System.out.println();
            }
        } else if (boardSize == 2) { 
            int i, j = 0;
            for (i = 0; i < nineArray.length; i++)
            {
                for (j = 0; j < nineArray.length; j++)
                    System.out.print(nineArray[i][j] + " ");
                System.out.println();
            }
    }
        int dataSelection = -1;     
        while (true)
        {
            Scanner rowColumn = new Scanner(System.in);
            System.out.println("Please select which way you would like to enter the values:" + "\n" + "1) row" + "\n" + "2) columnn");
            dataSelection = rowColumn.nextInt();
            if (dataSelection == 1 || dataSelection == 2) {
                break;
            }
        }
        //Entering by ROWS
        //This is for a 4x4 board size using rows
        if (dataSelection == 1) {
            if (boardSize == 1) {
                int row = 1;
                while (row < 5) {
                    String row1Values4x4 = "-1";
                    while (true) {
                        Scanner firstRow4x4 = new Scanner(System.in);
                        System.out.println("Please enter four values using commas for row " + row); //this needs to loop
                        row1Values4x4 = firstRow4x4.next();
                        row1Values4x4 = row1Values4x4.replaceAll(" ",""); //this is in case user enters numbers with spaces
                        if (row1Values4x4.length() == 7) {
                            break;
                        }
                    }
                    String strArray[] = row1Values4x4.split(",");
                    int arraySidesInteger[] = new int[strArray.length];
                    for (int i = 0;  i < strArray.length;  i++) {
                        arraySidesInteger[i] = Integer.parseInt(strArray[i]);
                    }
                    fourArray[row-1] = arraySidesInteger;
                    for (int i = 0; i < fourArray.length; i++) {
                        for (int j = 0; j < fourArray.length; j++)
                            System.out.print(fourArray[i][j] + " ");
                        System.out.println();
                    }
                    row++;
                }
                //This is for a 9x9 board size using rows 
                } else { 
                    int row = 1;
                    while (row < 10) {
                        String row1Values9x9 = "-1";
                        while (true) {
                            Scanner firstRow9x9 = new Scanner(System.in);
                            System.out.println("Please enter nine values using commas for row " + row); //this needs to loop
                            row1Values9x9 = firstRow9x9.next();
                            row1Values9x9 = row1Values9x9.replaceAll(" ",""); //this is in case user enters numbers with spaces
                            if (row1Values9x9.length() == 17) {
                                break;
                            }
                        }
                        String strArray[] = row1Values9x9.split(",");
                        int arraySidesInteger[] = new int[strArray.length];
                        for (int i = 0;  i < strArray.length;  i++) {
                            arraySidesInteger[i] = Integer.parseInt(strArray[i]);
                        }
                        nineArray[row-1] = arraySidesInteger;
                        for (int i = 0; i < nineArray.length; i++) {
                            for (int j = 0; j < nineArray.length; j++)
                                System.out.print(nineArray[i][j] + " ");
                            System.out.println();
                        }
                        row++;
                    }
                }
            //Entering by COLUMNS
            //This is for 4x4 board size using columns 
            } else { 
                if (boardSize == 1) {
                    int column = 1;
                    while (column < 5) {
                        String column1Values4x4 = "-1"; 
                        while (true) {
                            Scanner firstColumn4x4 = new Scanner(System.in);
                            System.out.println("Please enter four values using commas for column " + column);
                            column1Values4x4 = firstColumn4x4.next();
                            column1Values4x4 = column1Values4x4.replaceAll(" ","");
                            if (column1Values4x4.length() == 7) {
                                break;
                            }
                        }
                        String strArray[] = column1Values4x4.split(",");
                        int arraySidesInteger[] = new int[strArray.length];
                        for (int i = 0;  i < strArray.length;  i++) {
                            arraySidesInteger[i] = Integer.parseInt(strArray[i]);
                        }
                        for (int i = 0; i < arraySidesInteger.length; i++) {
                            fourArray[i][column-1] = arraySidesInteger[i];
                        }
                        for (int i = 0; i < fourArray.length; i++) {
                            for (int j = 0; j < fourArray.length; j++)
                                System.out.print(fourArray[i][j] + " ");
                            System.out.println();
                        }
                        column++;
                    }
                //This is for a 9x9 board size using columns
                } else { 
                    int column = 1;
                    while (column < 10) {
                        String column1Values9x9 = "-1";
                        while (true) {
                            Scanner firstColumn9x9 = new Scanner(System.in);
                            System.out.println("Please enter nine values using commas for column " + column);
                            column1Values9x9 = firstColumn9x9.next();
                            column1Values9x9 = column1Values9x9.replaceAll(" ","");
                            //row1Values4x4 = row1Values4x4.replaceAll(",","");
                            if (column1Values9x9.length() == 17) {
                                break;
                            }
                        }
                        String strArray[] = column1Values9x9.split(",");
                        int arraySidesInteger[] = new int[strArray.length];
                        for (int i = 0;  i < strArray.length;  i++) {
                            arraySidesInteger[i] = Integer.parseInt(strArray[i]);
                        }
                        for (int i = 0; i < arraySidesInteger.length; i++) {
                            nineArray[i][column-1] = arraySidesInteger[i];
                        }
                        for (int i = 0; i < nineArray.length; i++) {
                            for (int j = 0; j < nineArray.length; j++)
                                System.out.print(nineArray[i][j] + " ");


                    System.out.println();
                    }
                    column++;
                }
            }
            for (int i = 0; i < fourArray.length; i++) {
                for(int j = i + 1; j < fourArray.length; j++) {
                    if(fourArray[i] == fourArray[j]) {
                        System.out.println("No Sudoku");
                    } else {
                        System.out.println("Sudoku!");
                    }
            }
        }
    }
}

Answer 1

由于这是家庭作业，我将尽量减少代码，但我认为如果您有更多关于 2D 数组的信息(其中一些相当棘手)，您会很好地理解它:

• 由于 fourArray 是一个数组数组，fourArray[i] 指的是一个数组(您可以将其视为二维数组的第 i 行数组)。
• 要访问数组数组中的单个整数，请使用 fourArray[i][j]。
• 如果您执行 myArray1 == myArray2(正如您的代码目前所做的那样)，它不会比较内容；相反，它会检查它们是否实际上是同一个数组(如果您先说 myArray1 = myArray2 就会发生这种情况)。
• 如果您确实想比较两个数组的内容，可以使用 Arrays.equals(myArray1, myArray2)。
• 由以上几点可知，fourArray.length是一维的大小； fourArray[x].length 是另一个维度的大小(其中 x 无关紧要，只要它在 0 和 之间>fourArray.length - 1).

为回应评论而添加:我的理解和假设是您试图避免二维 fourArray 中包含的任何值之间的任何重复值。有许多解决方案。

可能被称为天真的解决方案是首先使用一对嵌套的 for 循环遍历 fourArray 中的每个值。对于这些值中的每一个，将其与其他所有值进行比较。您的中间代码可能如下所示:

for (int i = 0; i < fourArray.length; i++) {
    for (int j = 0; j < fourArray[i].length; j++) {
        // TODO: Compare value at (i,j) to every other point by nesting
        // two more for loops with new iterators (called, e.g., m and n)
        // TODO: If a duplicate is found, either stop searching, or at
        // least mark that a duplicate has been found somehow.
    }
}

一方面，这有点低效。另一方面，对于小型二维数组，它在计算上仍然完全微不足道，所以如果它对你有意义，那就去做吧，然后继续解决其他问题。

但是，如果您有兴趣并假设允许的值是连续集合的一部分(即，在典型的数独游戏中，您有 3x3 的框，其中允许的值是总是 1-9，永远不会更高)。如果您有一个数组 count[] 来跟踪这些已知值出现了多少次会怎么样？因此其中的所有值都将初始化为零。当您遍历表中的每个点时(如上面的代码示例所示)，您可以使用找到的值——称之为 v——来增加 count[v]。 count[] 中任何大于 1 的值都表示重复。