JAVA 连接四种方法错误地递减行

Question

我已经为 connectFour 编写了一个程序，它接受：

用户输入为 int（作为变量选择）
count int（根据 returns char for R or Y 插入多维数组的方法自动计算的变量）

然后我编写了一个名为 dropChip 的方法，它接受如下选择和计数值：

public static void dropChip(int selection, int count)
{   
  --selection;//make selection a human number
  if (grid[r][selection] == ' ')//while r(row) & selection is empty char
  {
     grid[r][selection] = userChip(count);//drop R or Y into grid   
  }
  else if (grid[r][selection] != ' ')//while r selection has a letter value
  {
     int x = r--;//set x to value of decremented r
     grid[x][selection] = userChip(count);//drop chip in next row of same column
  }
}

这是我在终端中的输出示例：

| | | | | | |
| | | | | | |
| | | | | | |
| | | | |R| |
| | | |Y| | |
| | |R| | | |

Yellow player's turn.
Input a value between 1 and 6 to drop your chip:  3

| | | | | | |
| | | | | | |
| | |Y| | | |
| | | | |R| |
| | | |Y| | |
| | |R| | | |

问题：为什么第 2 列（人类为 3 个）中的 Y 和 R 没有直接堆叠在一起？ r 的值应该是方法调用的局部值，而不是全局设置为负值，对吧？是什么赋予了？

在这里添加完整的程序以防有人想看得更深：

import java.util.*;
//create connectFour class
public class connectFour 
{   //main method and public declarations
    public static Scanner input = new Scanner(System.in);
    public static int selection = 0; 
    //create variable for square multidimensional array usage
    public static int y = 6;
    //build new two dimensional array of 3 rows with 3 columns
    public static char[][] grid = new char[y][y];
    public static int r = grid.length - 1;//6 as human number
    public static int c = grid[r].length - 1;//6 as human number

    public static void main(String[] args)
    {
        System.out.println();
        System.out.println("===============START PROGRAM===============\n");
        //create game prompt
        String prompt = "Welcome to the classic Connect Four game!\n\nThis program will start with the red player\nthen move to the yellow player.\n\nYou will chose a numerical value\nbetween 1 and 6 as the column to drop your chip.\n\nOnce you have dropped your chip, the program will scan\nthe columns and rows looking for a win.\nYou can win by having four chips stacked either\nhorizontally, vertically or diagonally.\n\nGood Luck!\n";
        System.out.print(prompt);

        //call the loadBlanks method with the variable of grid
        loadBlanks(grid);
        controller();
        //check4Win(grid, selection);
        System.out.println("===============END PROGRAM===============");
    }   

    public static void controller()
    {
        //set maximum number of user attempts (36 in this case)
        int maxAttempts = r * c;
        //create an empty int
        int count = 0;
        //while the count value is less than maxAttempts
        while (count < maxAttempts)
        {
        //determine which user turn it is sending count number
            userTurn(count);
            //print prompt for user disc
            System.out.print("Input a value between 1 and 6 to drop your chip:  ");
            //store user value in selection
            selection = input.nextInt();
            System.out.println();
            //send human number of selection to method that drops chip along with count value
            dropChip(selection, count);
            //print the connect four game
            printValues(grid);
            //increment value of count
            count++;
        }
    }

    public static void loadBlanks(char[][] grid)
    {//while row is < total count of rows
        for (int row = 0; row < grid.length; row++)
        {//while column in row is < total count of columns  
            for (int column = 0; column < grid[row].length; column++)
            {//fill grid with blank values
                grid[row][column] = ' ';
            }//end inner loop
        }//end outer loop
    }

    public static void dropChip(int selection, int count)
    {   
        --selection;//make selection a human number
        int x = grid.length - 1;
        if (grid[x][selection] == ' ')
        {
            grid[x][selection] = userChip(count);   
        }

        else if (grid[x][selection] == 'R' || grid[x][selection] == 'Y')//(grid[x][selection] == 'R' || grid[r][selection] == 'Y')
        {
            grid[x-1][selection] = userChip(count);
        }
    }

    //print all of the values in the array 
    public static void printValues(char[][] grid)
    {//while row is < total count of rows
        for (int row = 0; row < grid.length; row++)
        {//while column in row is < total count of columns
            for (int col = 0; col < grid[row].length; col++)
            {//print inner loop bracket
                System.out.print("|" + grid[row][col]);
            }//end inner loop
        System.out.println("|");//print outer loop bracket
        }//end outer loop
    }

    //return the value of the user chip based on turn as char
    public static char userChip(int count)
    {
        //set userColor to random value
        char userColor = ' ';

        //if the passed value of int x is evenly divisibly by 2, set char to R
        if (count % 2 == 0)
        {
            userColor = 'R';
        }//end if
        //else if the int of x modulo 2 != 0, set char to Y
        else if (count % 2 != 0)
        {
            userColor = 'Y';
        }//end elseif
        return userColor;//set value of char to userColor
    }

    //calculate user turn based on count value starting with red
    public static void userTurn(int count)
    {
        String color = " ";
        if (count % 2 == 0)
        {
            color = "Red";
        }//end if
        //else if the int of x modulo 2 != 0, set char to Y
        else if (count % 2 != 0)
        {
            color = "Yellow";
        }//end elseif
        System.out.println();//whitespace for terminal
        System.out.println(color + " player\'s turn.");//print user turn
    }

Answer 1

好的，从字面上调试您的代码。我在你的 static void dropChip(int selection, int count) 方法声明中看到了这个 -

else if (grid[x][selection] == 'R' || grid[x][selection] == 'Y') {
            grid[x - 1][selection] = userChip(count);
      }

这就是避免重叠的原因。因为如果您在当前块中找到 'R' 或 'Y'，您会将新字符放置在同一列（就在其上方）的网格的 x-1 行中。

如果您只想覆盖当前块中的现有值，您可以将 dropChip 方法更改为 -

public static void dropChip(int selection, int count) {
  --selection;
  int x = grid.length - 1;
  grid[x][selection] = userChip(count);
}

此外，如果您改为使用

int x = r--;

然后是行数，每次到达此语句时都会减 1。导致向上块填充问题中共享的样本输出。

Edit - 附带说明，因为您在 controller 中只接受单一输入，所以我不接受查看您想要填充当前逻辑中倒数第二行以上的行（或更新逻辑中的最后一行。）

建议 - 尝试根据行和列进行输入，以便用所需的字符填充确切的块。

Answer 2

我昨天很晚才找到答案。通过使用 r 的全局值，只要 --r 选择的值等于 R 或 Y 字符，我的代码就会在全局范围内递减该值。为了解决这个问题，我使用了一个带有 x 的局部 for 循环，其中 x = grid.length-1 并在每次通过该方法时递减该值。我的 dropChip 方法的工作示例如下。感谢大家的comments/help!

public static void dropChip(int selection, int count)
{   
    --selection;//make selection a human number
    for (int x = grid.length-1; x >= 0; --x)//set x to value of decremented r
    {
        if (grid[x][selection] == ' ')//while r(row) & selection is empty char
            {
                grid[x][selection] = userChip(count);//drop R or Y into grid  
                break; 
            }
            //else grid[x][selection] = userChip(count);//drop chip in next row of same column
    }

}

JAVA 连接四种方法错误地递减行

JAVA Connect Four Method Incorrectly Decrements Row

java

arrays

multidimensional-array

decrement