如何存储数组槽以在函数之间使用？

Question

我正在尝试制作一个井字游戏，让您可以与人类敌人或计算机对战。我正在尝试编写一些基本的 AI 代码，通过扫描板来查看您是否有 2 个 X 或 O 彼此相邻或在列/行/对角线的对角中，这将阻止您获胜，我需要一种方法来告诉计算机是否需要打印以及需要在哪个图块上打印以防止您获胜。我的代码：

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

void initializeBoard(); //initialize the board //
void drawBoard(); //draw it on the window //
void player_1_move(); //check if player 1 made a valid move and update the board
void player_2_move(); //check if player 2 made a valid move and update the board

//AI functions
void pickTile(); //picks a tile based on available information
void computerTurn(); //checks if the computer is going first or second

char* isThereaWinningMove(); //checks if the user is abou to win
char tempcT;

int checkWin(); //checks if either player has won at the end of every turn and if so ends the game and declares a winner //

char board[3][3]; //3x3 tic tac toe board

int main(){
    
    int win = 0;
    
    printf("==============");
    printf("\n TIC TAC TOE \n");
    printf("==============\n");
    printf("The World's Number 1 Multiplayer Game! \n\n");
    
    initializeBoard();
    
    //let's the user pick the gamemode
    int x;
    
    printf("Press 1 to PLAY AGAINST A HUMAN or 0 to PLAY AGAINST AI: \n");
    scanf("%d", &x);
    
    while(x!=0 && x!=1){
        printf("Invalid input. Press 1 to PLAY AGAINST A HUMAN or 0 to PLAY AGAINST AI: ");
        scanf("%d", &x);
    }
    if(x==1){ //pvp
        do{
            drawBoard();
            printf("\n\n");
        
            player_1_move(); //player 1 (X) moves
            drawBoard(); //update the board with each move
            win=checkWin(); //did player 1 win?
            if(win==1){
                printf("\nPlayer 1 has won!");
                break;
            }
            
            printf("\n\n");
            player_2_move(); //player 2 (O) moves
            drawBoard(); //update the board with each move
            win=checkWin(); //did player 2 win?
            if(win==1){
                printf("\nPlayer 2 has won!");
                break;
            }
        }while(1);
    }
    else{ //pvc
        computerTurn();
        if(tempcT == 'O'){ //if the player is going first
            do{
                srand( (unsigned int) time(NULL) ); //initialize random seed
                drawBoard();
                printf("\n\n");
            
                player_1_move(); //user (X) moves first
                drawBoard(); //update the board with each move
                win=checkWin(); //did player 1 win?
                if(win==1){
                    printf("\nPlayer has won!");
                    break;
                }
                //computer turn
                printf("\n\n");
                pickTile(); //picks available tile
                win=checkWin();
                if(win == 1){
                    printf("\nI win!");
                    break;
                }
            }while(1);
        }
        else{ //if the computer goes first
            do{
                
                //computer turn
                srand( (unsigned int) time(NULL) ); //initialize random seed
                printf("\n\n");
                pickTile(); //picks available tile
                win=checkWin();
                if(win == 1){
                    printf("\nI win!");
                    break;
                }
                
                //player turn
                drawBoard();
                printf("\n\n");
            
                player_1_move(); //user (X) moves first
                drawBoard(); //update the board with each move
                win=checkWin(); //did player 1 win?
                if(win==1){
                    printf("\nPlayer has won!");
                    break;
                }
            }while(1);
        }
    }
    return 0;
}

//initialize the board
void initializeBoard(){
    
    int i, j;
    
    for(i=0; i<=2; i++){
        for(j=0; j<=2; j++){
            board[i][j]= ' ';
        }
    }
    
}

//draws the board on the window
void drawBoard(){
    int t;
    
    for(t=0; t<=2; t++){
        printf(" %c | %c | %c ", board[t][0], board[t][1], board[t][2]);
        if(t!=2){
            printf("\n---|---|---\n");
        }
    }
    printf("\n");
}

//checks if there is a winner at the end of every turn
int checkWin(){
    
    int i;
    
    //checks rows
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][1] && board[i][0]==board[i][2] && board[i][0]!= ' '){
            return 1;
        }
    }
    
    //checks columns
    for(i=0; i<=2; i++){
        if(board[0][i]==board[1][i] && board[0][i]==board[2][i] && board[0][i]!= ' '){
            return 1;
        }
    }
    
    //checks diagonals from top left to bottom right
    for(i=0; i<=2; i++){
        if(board[0][0]==board[1][1] && board[1][1]==board[2][2] && board[0][0]!= ' '){
            return 1;
        }
    }
    
    //checks diagonals from bottom left to top right
    for(i=0; i<=2; i++){
        if(board[2][0]==board[1][1] && board[1][1]==board[0][2] && board [2][0]!= ' '){
            return 1;
        }
    }
    
    return 0;
}

//player 1 (X) move
void player_1_move(){
    
    int x, y;
    
    //player 1 picks coordinates on the board
    printf("Player 1, please pick a row (1-3): ");
    scanf("%d", &x);
    printf("Now pick a column (1-3): ");
    scanf("%d", &y);
    
    x--, y--;
    
    //check if it's a valid tile
    while(1){
        if(x<0 || x>2){
            if(y<0 || y>2){
                printf("Invalid tile, please enter a valid tile (same order as before, 1-3): ");
                scanf("%d%d", &x, &y);
                x--, y--;
            }
            else{
                printf("Invalid row, please try again (1-3): ");
                scanf("%d", &x);
                x--;
            }
        }
        else if(y<0 || y>2){
            printf("Invalid column, please try again (1-3): ");
            scanf("%d", &y);
            y--;
        }
        else{
            break;
        }
    }
    
    //check if the tile is free
    while(board[x][y]=='O' || board[x][y]=='X'){
        printf("Invalid move, please enter valid coordinates (same order as before, 1-3): ");
        scanf("%d%d", &x, &y);
        x--, y--;
    }
    
    board[x][y]='X';
}

//player 2 (O) move
void player_2_move(){
    
    int x, y;

    //player 2 picks a tile
    printf("Player 2, please pick a row (1-3): ");
    scanf("%d", &x);
    printf("Now pick a column (1-3): ");
    scanf("%d", &y);
    x--, y--; 

    //check if it's a valid tile
    while(1){
        if(x<0 || x>2){
            if(y<0 || y>2){
                printf("Invalid tile, please enter a valid tile (same order as before, 1-3): ");
                scanf("%d%d", &x, &y);
                x--, y--;
            }
            else{
                printf("Invalid row, please try again (1-3): ");
                scanf("%d", &x);
                x--;
            }
        }
        else if(y<0 || y>2){
            printf("Invalid column, please try again (1-3): ");
            scanf("%d", &y);
            y--;
        }
        else{
            break;
        }
    }
    
    //check if the tile is free
    while(board[x][y]=='O' || board[x][y]=='X'){
        printf("Invalid move, please enter valid coordinates (same order as before, 1-3): ");
        scanf("%d%d", &x, &y);
        x--, y--;
    }
    
    board[x][y]='O';
}

//AI functions

//checks if the computer is going first or second
void computerTurn(){
    
    int x;
    
    printf("Press 1 if you'd like to GO FIRST and 0 if you'd like to GO SECOND: ");
    scanf("%d", &x);
    while(x!=0 && x!=1){
        printf("Invalid input. Press 1 if you'd like to GO FIRST and 0 if you'd like to GO SECOND: ");
        scanf("%d", &x);
    }
    if(x==1){
        printf("OK, the player is going first.\n\n");
        tempcT = 'O';
    }
    else{
        printf("OK, I'm going first.\n\n");
        tempcT = 'X';
    }
}

//if there is a winning move available on the AI's turn
char* isThereaWinningMove(){
    int i;
    
    //checks rows
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][1] && board[i][1] == ' '){
            return &board[i][2];
        }
    }
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][2] && board[i][1] == ' '){ 
            return &board[i][1];
        }
    }
    for(i=0; i<=2; i++){
        if(board[i][1]==board[i][2] && board[i][0] == ' '){
            return &board[i][0];
        }
    }
    
    //checks columns
    for(i=0; i<=2; i++){
        if(board[0][i]==board[2][i] && board[1][i] == ' '){
            return &board[1][i];
        }
    }
    for(i=0; i<=2; i++){
        if(board[0][i]==board[1][i] && board[2][i] == ' '){
            return &board[2][i];
        }
    }
    for(i=0; i<=2; i++){
        if(board[1][i]==board[2][i] && board[0][i] == ' '){
            return &board[0][i];
        }
    }
    
    //checks diagonals from top left to bottom right
    if(board[1][1]==board[2][2] && board[0][0] == ' '){
        return &board[0][0];
    }
    if(board[0][0]==board[2][2] && board[1][1] == ' '){
        return &board[1][1];
    }
    if(board[0][0]==board[1][1] && board[2][2] == ' '){
        return &board[2][2];
    }
    //checks diagonals from bottom left to top right
    if(board[1][1]==board[0][2] && board [2][0] == ' '){
        return &board[2][0];
    }
    if(board[2][0]==board[1][1] && board [0][2] ==' '){
        return &board[0][2];
    }
    if(board[2][0]==board[0][2] && board [1][1] == ' '){
        return &board[1][1];
    }
    return 0;
}

//picks a tile based on available information
void pickTile(){
    int rndX, rndY;
    char *p = isThereaWinningMove();
    
    //did the computer detect a winning move?
    if(p != 0){
        *p = tempcT;
    }
    
    //if not, pick a random available tile
    else{
        while(1){
            rndX = rand()%3;
            rndY = rand()%3;
            
            if(board[rndX][rndY] == ' '){
                board[rndX][rndY] = tempcT;
                break;
            }
        }
    }
}

与人类对战似乎效果很好。我只有将 tempcT 的值分配给 isThereaWinningMove 函数将返回的任何数组槽的问题。由于 2 个编译器错误，我现在编写的代码实际上并没有运行：

[错误] 函数 'char isThereaWinningMove()' 的赋值 [错误] 在赋值中无法将'int'转换为'char()'

Answer 1

正如我通过对您的问题的评论所说的那样：

[错误] 函数 'char isThereaWinningMove()' 的赋值 [错误] 无法在赋值中将 'int' 转换为 'char()'

isThereaWinningMove 是一个函数，做isThereaWinningMove = 'tempcT' you try to assign a function with an (invalid) char 毫无意义。

其他一些评论：

• 除此之外，您多次调用 isThereaWinningMove 都是徒劳的，因为您失去了结果。

• scanf("%d", x)是你想要的无效scanf("%d", &x)

• 您多次调用 srand 时使用的值很可能相同（程序在同一秒内运行），因此您很可能为所有 rndX 和rndY，你必须在main开始时调用一次srand。

实际上你想修改由isThereaWinningMove返回值的单元格，在C（然后是C++）中你可以返回单元格的地址而不是单元格的值：

char * isThereaWinningMove(); //checks if there is a winning move available

...

char * isThereaWinningMove(){
    int i;
    
    //checks rows
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][1] && board[i][0]!= ' '){
            return &board[i][2];
        }
    }
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][2] && board[i][0]!= ' '){ 
            return &board[i][1];
        }
    }
    for(i=0; i<=2; i++){
        if(board[i][1]==board[i][2] && board[i][0]!= ' '){
            return &board[i][0];
        }
    }
    
    //checks columns
    for(i=0; i<=2; i++){
        if(board[0][i]==board[2][i] && board[0][i]!= ' '){
            return &board[1][i];
        }
    }
    for(i=0; i<=2; i++){
        if(board[0][i]==board[1][i] && board[0][i]!= ' '){
            return &board[2][i];
        }
    }
    for(i=0; i<=2; i++){
        if(board[1][i]==board[2][i] && board[0][i]!= ' '){
            return &board[0][i];
        }
    }
    
    //checks diagonals from top left to bottom right
    if(board[1][1]==board[2][2] && board[0][0]!= ' '){
        return &board[0][0];
    }
    if(board[0][0]==board[2][2] && board[0][0]!= ' '){
        return &board[1][1];
    }
    if(board[0][0]==board[1][1] && board[0][0]!= ' '){
        return &board[2][2];
    }
    //checks diagonals from bottom left to top right
    if(board[1][1]==board[0][2] && board [2][0]!= ' '){
        return &board[2][0];
    }
    if(board[2][0]==board[1][1] && board [2][0]!= ' '){
        return &board[0][2];
    }
    if(board[2][0]==board[0][2] && board [2][0]!= ' '){
        return &board[1][1];
    }
    return 0;
}

...

void pickTile(){
    int rndX, rndY, i;
    
    //did the computer detect a winning move?
    char * p = isThereaWinningMove();
    
    if(p != 0){
        *p = tempcT;
    }
    
    //if not, pick a random available tile
    else{
...

另一种方法是在 isThereaWinningMove 中进行分配，并在您执行此操作时返回 0

int isThereaWinningMove(); //checks if there is a winning move available

...

int isThereaWinningMove(){
    int i;
    
    //checks rows
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][1] && board[i][0]!= ' '){
            board[i][2] = tempcT;
            return 1;
        }
    }
    for(i=0; i<=2; i++){
        if(board[i][0]==board[i][2] && board[i][0]!= ' '){ 
            board[i][1] = tempcT;
            return 1;
        }
    }
    for(i=0; i<=2; i++){
        if(board[i][1]==board[i][2] && board[i][0]!= ' '){
            board[i][0] = tempcT;
            return 1;
        }
    }
    
    //checks columns
    for(i=0; i<=2; i++){
        if(board[0][i]==board[2][i] && board[0][i]!= ' '){
            board[1][i] = tempcT;
            return 1;
        }
    }
    for(i=0; i<=2; i++){
        if(board[0][i]==board[1][i] && board[0][i]!= ' '){
            board[2][i] = tempcT;
            return 1;
        }
    }
    for(i=0; i<=2; i++){
        if(board[1][i]==board[2][i] && board[0][i]!= ' '){
            board[0][i] = tempcT;
            return 1;
        }
    }
    
    //checks diagonals from top left to bottom right
    if(board[1][1]==board[2][2] && board[0][0]!= ' '){
        board[0][0] = tempcT;
        return 1;
    }
    if(board[0][0]==board[2][2] && board[0][0]!= ' '){
        board[1][1] = tempcT;
        return 1;
    }
    if(board[0][0]==board[1][1] && board[0][0]!= ' '){
        board[2][2] = tempcT;
        return 1;
    }
    //checks diagonals from bottom left to top right
    if(board[1][1]==board[0][2] && board [2][0]!= ' '){
        board[2][0] = tempcT;
        return 1;
    }
    if(board[2][0]==board[1][1] && board [2][0]!= ' '){
        board[0][2] = tempcT;
        return 1;
    }
    if(board[2][0]==board[0][2] && board [2][0]!= ' '){
        board[1][1] = tempcT;
        return 1;
    }
    return 0;
}

...

//picks a tile based on available information
void pickTile(){
    int rndX, rndY, i;
    
    //did the computer detect a winning move?
    if (isThereaWinningMove() == 0){
        //if not, pick a random available tile
        while(1){
...

不管怎么做，也去掉pickTile中无用的变量i，去掉mainisThereaWinningMove的调用/em> 执行时会出现一些其他问题，例如我可以：

pi@raspberrypi:/tmp $ gcc -Wall t.cpp 
pi@raspberrypi:/tmp $ ./a.out


 TIC TAC TOE 

The World's Number 1 Multiplayer Game! 

Press 1 to PLAY AGAINST A HUMAN or 0 to PLAY AGAINST AI: 0
Press 1 if you'd like to GO FIRST and 0 if you'd like to GO SECOND: 1
OK, the player is going first.   |   |   
---|---|---
   |   |   
---|---|---
   |   |   


Player 1, please pick a row (1-3): 2
Now pick a column (1-3): 2
   |   |   
---|---|---
   | X |   
---|---|---
   |   |   


   |   |   
---|---|---
   | X |   
---|---|---
 O |   |   


Player 1, please pick a row (1-3): 1
Now pick a column (1-3): 1
 X |   |   
---|---|---
   | X |   
---|---|---
 O |   |   


 O |   |   
---|---|---
   | X |   
---|---|---
 O |   |   


Player 1, please pick a row (1-3): ^C
pi@raspberrypi:/tmp $ 

如你所见，程序得到了我之前得到的单元格 1-1。

原因很简单，isThereaWinningMove`可以在不检查是否空闲的情况下获取单元格，例如

    if(board[i][0]==board[i][1] && board[i][0]!= ' '){
        board[i][2] = tempcT;
    return 1;
    }

必须

    if((board[i][0]==board[i][1] && board[i][0]!= ' ') && (board[i][2] == ' ')) {
        board[i][2] = tempcT;
    return 1;
    }

等

注意还有两个错误的索引，例如使用第二种方式

for(i=0; i<=2; i++){
    if(board[i][1]==board[i][2] && board[i][0]!= ' '){
        board[i][0] = tempcT;
    return 1;
    }
}

你想要（在缺少的测试中检查单元格是否为空）

for(i=0; i<=2; i++){
    if(board[i][1]==board[i][2] && board[i][1]!= ' '){
        board[i][0] = tempcT;
    return 1;
    }
}

为了

for(i=0; i<=2; i++){
    if(board[1][i]==board[2][i] && board[0][i]!= ' '){
        board[0][i] = tempcT;
    return 1;
    }
}

您想要（在缺少的测试中检查单元格是否为空）：

for(i=0; i<=2; i++){
    if(board[1][i]==board[2][i] && board[1][i]!= ' '){
        board[0][i] = tempcT;
    return 1;
    }
}

注意 checkWin 中的循环是无用的：

//checks diagonals from top left to bottom right
for(i=0; i<=2; i++){
    if(board[0][0]==board[1][1] && board[1][1]==board[2][2] && board[0][0]!= ' '){
        return 1;
    }
}

//checks diagonals from bottom left to top right
for(i=0; i<=2; i++){
    if(board[2][0]==board[1][1] && board[1][1]==board[0][2] && board [2][0]!= ' '){
        return 1;
    }
}

够了

if(board[0][0]==board[1][1] && board[1][1]==board[2][2] && board[0][0]!= ' '){
    return 1;
}
if(board[2][0]==board[1][1] && board[1][1]==board[0][2] && board [2][0]!= ' '){
    return 1;
}