C:创建一个游戏，但在某些情况下，我会因为一个错误和无限循环错误而失败

Question

我在C语言的入门课上，我的教授布置我们为我们现在的作业编写一个叫做“茶话会”的游戏。我已经完成了这个游戏的编码，它在很大程度上是可以工作的，但是有一些我似乎不能解决的问题。

游戏规则很简单:两个玩家轮流旋转旋转器(通过输入"0“并按enter键来模拟)，并为茶话会收集所有7件物品。第一个获得全部7个物品的玩家获胜。唯一的问题是，除非你先有一个盘子，否则你不能收集三明治、水果或甜点。如果你落在“输掉一块”方块上，你必须放弃其中一块。这两个错误都来自游戏中的lose a game实例，所以我认为这个错误一定是来自"get_lost_piece“函数。

其中之一是"player“数组中的片段编号奇怪，因为它们比正常值高出1个值。另一个错误是，当玩家试图在他们有一个需要盘子的物品时移走他们的盘子时，它应该打印出“对不起，没有盘子吃饭是不礼貌的。输入另一个选择：”，但是，我得到了一个无限循环，上面写着“你丢失了物品1”。

下面是我的代码：

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

    #define SLOW_MODE 1

    #define NUMPLAYERS 2
    #define NUMPIECES 7
    #define MAXLEN 20
    #define NO_WINNER -1

    const char CHOICES[NUMPIECES+1][MAXLEN] = {"PLATE", "NAPKIN", "TEA CUP", "CREAM AND    SUGAR", "SANDWICH", "FRUIT", "DESSERT", "LOSE A PIECE"};

        void update_player(int player[], int square);
    int get_lost_piece(int player[]);
    int search(int piece_list[], int choice);
    int get_spin();
    void init_player(int player[]);
    int get_winner(int players[][NUMPIECES]);
    int get_next_player(int player_num);
    int count_pieces(int player[]);
    void print_player(int player[], int player_num);

    int main() {

    srand(time(0));

    int players[NUMPLAYERS][NUMPIECES];

    // Initialize each player in the game.
    int i;
    for (i=0; i<NUMPLAYERS; i++)
        init_player(players[i]);

    int player_number = 0;

    // Play until we get a winner.
    int status = get_winner(players);
    while (status == NO_WINNER) {

        int dummy;

        // In slow mode, we stop before every spin.
        if (SLOW_MODE) {
            printf("Player %d, it is your turn. Type 0 and enter to spin.\n", player_number+1);
            scanf("%d", &dummy);
        }

        // Get the current player's spin and print out her pieces.
        int square = get_spin();
        printf("Player %d, have landed on the square %s.\n", player_number+1, CHOICES[square]);
        update_player(players[player_number], square);
        print_player(players[player_number], player_number+1);

        // Update the game status.
        player_number = get_next_player(player_number);
        status = get_winner(players);
        printf("\n\n");
    }

    printf("Congrats player %d, you win!\n", status+1);

    return 0;
}

    // Pre-conditions: player stores the contents of one player and square is in between 0 and 7, inclusive.
    // Post-conditions: The turn for player will be executed with the given square selected.
void update_player(int player[], int square) {

    if (square == 7) {

        if (count_pieces(player) == 0)
        {
            printf("There is no piece for you to lose. Lucky you, sort of.\n");
            return;
        }

        else{
            int q;
            q = get_lost_piece(player);
            player[q]= 0;

        }
        return;
    }

    player[square]=search(player, square);

    // Restricted by having no plate!
    if (player[0] == 0) {

       if(square == 4 || square == 5 ||square == 6){
        printf("Sorry, you can't obtain that item because you don't have a plate yet.\n");}

        else{
            if (player[square] == 0){
                player[square]++;
        }
        }
        }

    // Process a regular case, where the player already has a plate.
    else {
        if (player[square] == 0){
            player[square]++;
        }
        }
    }


    // Pre-conditions: player stores the contents of one player that has at least one piece.
    // Post-conditions: Executes asking a player which item they want to lose, and reprompts them
//                  until they give a valid answer.
int get_lost_piece(int player[]) {


    int choice = -1;



    // Loop until a valid piece choice is made.
    while (1) {
    if (choice == -1){
        printf("Which piece would you like to lose?\n");
        print_player(player,choice);
        scanf("%d", &choice);}
    if (player[choice] == 0 && choice < 7 && choice >= 0){
        printf("Sorry, that was not one of the choices");
        scanf("%d", &choice);
        }
    if (player[0] == 1 && choice == 4 || choice == 5 ||choice == 6){
        printf("Sorry, it is bad manners to eat without a plate. Enter another choice:\n");
        scanf("%d", &choice);
        }

    else{
        printf("You lost piece %d\n", choice);
        }
    }

    return choice;
}

// Pre-conditions: piece_list stores the contents of one player
// Post-conditions: Returns 1 if choice is in between 0 and 6, inclusive and corresponds to
//                  an item in the piece_list. Returns 0 if choice is not valid or if the
//                  piece_list doesn't contain it.
int search(int piece_list[], int choice) {

    int i;
    for (i=0; i<NUMPIECES; i++){
        if(piece_list[i]==choice){
           return 1;}
        else {return 0;}
    }
}
// Pre-condition: None
// Post-condition: Returns a random value in between 0 and 7, inclusive.
int get_spin() {

   return rand() % 8;

}

// Pre-condition: None
// Post-condition: Initializes a player to have no pieces.
void init_player(int player[]) {

  int j;

  for (j=0; j< NUMPIECES; j++)
    player[j]=0;

}

// Pre-condition: players stores the current states of each player in the tea party game.
// Post-condition: If a player has won the game, their 0-based player number is returned.
//                 In the case of no winners, -1 is returned.
int get_winner(int players[][NUMPIECES]) {

   int i =0;
  for (i=0; i<NUMPLAYERS; i++){
    if(count_pieces(players[i]) == NUMPIECES) {
        return i;}
  }
 return -1;


}

// Pre-condition: 0 <= player_num < NUMPLAYERS
// Post-condition: Returns the number of the next player, in numerical order, with
//                 a wrap-around to the beginning after the last player's turn.
int get_next_player(int player_num) {

    player_num++;
    if (player_num == NUMPLAYERS){
        player_num = 0;
    }
    return player_num;

}


// Pre-conditions: player stores the contents of one player
// Post-conditions: Returns the number of pieces that player has.
int count_pieces(int player[]) {

    int y, counter;

    counter = 0;

    for ( y = 0; y < 7; y++){
        if(player[y] == 1){
        counter++;
        }
    }
return counter;
}

// Pre-conditions: player stores the contents of one player and player_num is that
//                 player's 1-based player number.
// Post-conditions: Prints out each item the player has, numbered with the numerical
//                  "codes" for each item.
void print_player(int player[], int player_num) {

    int i;

    printf("\n");
    printf("Player %d\n", player_num);

    for (i=0; i < 7; i++){
        if (player[i] == 1){
            printf("%d. %s\n", i + 1, CHOICES[i]);
        }
    }

}

提前感谢您的帮助。我感觉解决方案就在我面前，但在这上面花了几天时间后，我很难发现问题所在。

Answer 1

• 需要将#include <stdlib.h>用于rand()，将player_number参数传递给get_lost_piece()并将其传递给print_player.

以下只是重构的一个想法。它可以通过许多不同的方式来完成。

• 在循环开始时获取一次输入。
• 在每个if语句中使用continue关键字来重做循环。

当我将get_lost_piece()的逻辑更改为：

 while...
     get choice
     if  choice < 1 || choice > 7   "1-7 please..." continue
     if  player[choice - 1] == 0   "sorry..." continue
     if  choice == 1  (and player[] contains foods)   "bad manners..." continue
 return choice - 1;

有用的提示

代码循环应该受到限制，并需要给播放器一个退出代码输出FAQ entry：scanf()返回错误，将内容留在输入流上。

• 尽早测试，经常测试。
• 出现编译器警告(由catcall建议)

<代码>F233