Connect4复刻版无法正确统计横向连续棋子问题求助

问题说明 #

我正在IDE中编写计算机科学1的期末作业，复刻Connect4游戏，但遇到两个问题：

• 玩家放置相邻棋子时，horizontalLeft和horizontalRight变量无法正确递增
• 调整leftCount/rightCount的位置后，在最右侧叠放棋子时游戏会莫名卡顿

原代码 #

//Sam Stevens
import java.util.*;
public class MyProgram
{
    public static void main(String[] args)
    {
        String[][] gameboard = new String[7][7];
        //first value "i" is the height, second "j" is the width.
        for(int i = 0; i< gameboard.length; i++){
        for(int j = 0; j< gameboard[0].length; j++){
        gameboard[i][j] = "_";
        }
        }
        //Initialize Gameboard
        print(gameboard);
        for(int i = 0; i < 10; i++){
        play(gameboard);
        }
        //this for loop makes the game last 10 turns
    }
        
        public static void print(String[][] gb){
            System.out.println("\n");
        for(int i = 0; i< gb.length; i++){
        for(int j = 0; j< gb[0].length; j++){
        System.out.printf("%-3s ", gb[i][j]);
        }
        System.out.println();
        }
        }
        //print out the gameboard
    
        public static void play(String[][] gb){
            Scanner input = new Scanner(System.in);
            boolean cont = true;
            do{
                System.out.println("Player 1, where would you like to go? (1,2,3,4,5,6,7)");
                int p1choice = input.nextInt() - 1;
                boolean moving = true;
                int i = 6;
                int j = p1choice;
                int yIndex = 0;
                do{
                    if(i>=0){
                    if(gb[i][j] == "_"){
                        gb[i][j] = "1";
                        moving = false;
                        yIndex = i;
                    }
                    i--;
                    }
                    else{
                        System.out.println("Invalid move. Sucks to be you.");
                        moving = false;
                    }
                }while(moving);
                print(gb);
                checkWin(gb, "1", p1choice, yIndex);
                
                System.out.println("Player 2, where would you like to go? (1,2,3,4,5,6,7)");
                int p2choice = input.nextInt() - 1;
                moving = true;
                i = 6;
                j = p2choice;
                int yIndexP2 = 0;
                do{
                    if(i>=0){
                    if(gb[i][j] == "_"){
                        gb[i][j] = "2";
                        moving = false;
                        yIndexP2 = i;
                    }
                    i--;
                    }
                    else{
                        System.out.println("Invalid move. Sucks to be you.");
                        moving = false;
                    }
                }while(moving);
                print(gb);
                checkWin(gb, "2", p2choice, yIndexP2);
            }while(!cont);
        }
        
        public static void checkWin(String[][] gb, String p, int heightIndex, int widthIndex){
            //p tells us which player we are checking for and we can use it as which piece we're looking for.
            int horizontalLeft = 0;
            int horizontalRight = 0;
            int verticalUp = 0;
            int verticalDown = 0;
            
            //check pieces to the left
            boolean leftContinue = true;
            if(widthIndex != 0){
                int leftCount = 1;
                do{
                    if(gb[heightIndex][widthIndex - leftCount] == p){
                        horizontalLeft ++;
                        leftCount ++;
                    }
                    else{
                        leftContinue = false;
                    }
                }while(leftContinue && (widthIndex - leftCount >= 0));
            }
            
            //check pieces to the right
            boolean rightContinue = true;
            if(widthIndex != 6){
                int rightCount = 1;
                do{
                    if(gb[heightIndex][widthIndex + rightCount] == p){
                        horizontalRight ++;
                        rightCount ++;
                    }
                    else{
                        rightContinue = false;
                    }
                }while(rightContinue && (widthIndex + rightCount <= 6));
            }
            
            System.out.println(p + " " + horizontalLeft + " " + horizontalRight);
            //BELOW HERE SHOULD BE ONLY CHECK WIN
            if(horizontalLeft + horizontalRight >= 3){
                System.out.println("Game over. Player " + p + " wins!");
            }
        }
}

问题根源与修复方案 #

1. 参数顺序传反（核心问题） #

调用checkWin方法时，错误地将**列索引（width）和行索引（height）**的顺序传反了：

• 原调用：checkWin(gb, "1", p1choice, yIndex);
• 正确调用：checkWin(gb, "1", yIndex, p1choice);

p1choice是玩家选择的列（width），yIndex是棋子落下的行（height），但checkWin方法的参数定义是int heightIndex, int widthIndex，传反后会在错误的行上检查相邻棋子，导致计数变量无法递增。

2. 字符串比较错误 #

Java中判断字符串内容相等必须使用equals()方法，而非==（==比较的是对象引用地址）。原代码中所有gb[...][...] == p的写法都要改成gb[...][...].equals(p)，否则无法正确识别相同玩家的棋子。

3. 循环逻辑优化（解决卡顿） #

调整循环条件的判断顺序，先检查索引是否合法，再判断棋子是否匹配，避免潜在的索引越界问题。同时确保leftCount/rightCount仅在匹配时自增，防止无效循环。

修复后的关键代码片段 #

修复后的play方法调用部分 #

// Player 1 调用修复
print(gb);
checkWin(gb, "1", yIndex, p1choice); // 交换yIndex和p1choice的顺序

// Player 2 调用修复
print(gb);
checkWin(gb, "2", yIndexP2, p2choice); // 交换yIndexP2和p2choice的顺序

修复后的checkWin方法 #

public static void checkWin(String[][] gb, String p, int heightIndex, int widthIndex){
    int horizontalLeft = 0;
    int horizontalRight = 0;
    int verticalUp = 0;
    int verticalDown = 0;

    // 检查左侧棋子
    int leftCount = 1;
    while (widthIndex - leftCount >= 0 && gb[heightIndex][widthIndex - leftCount].equals(p)) {
        horizontalLeft++;
        leftCount++;
    }

    // 检查右侧棋子
    int rightCount = 1;
    while (widthIndex + rightCount <= 6 && gb[heightIndex][widthIndex + rightCount].equals(p)) {
        horizontalRight++;
        rightCount++;
    }

    System.out.println(p + " " + horizontalLeft + " " + horizontalRight);
    if(horizontalLeft + horizontalRight >= 3){
        System.out.println("Game over. Player " + p + " wins!");
    }
}

额外优化建议 #

• 游戏结束后应终止循环，当前代码的for(int i=0; i<10; i++)会强制进行10回合，可在checkWin中添加退出逻辑
• 无效输入处理可优化，比如玩家输入超出1-7范围时重新提示，而非直接结束移动
• 垂直方向的胜利检测尚未实现，可参考水平检测的逻辑完成

内容的提问来源于stack exchange，提问作者Sam Stevens