学习C++：生命的游戏

Question

这里的学生Java开发人员正在寻找一些帮助，用一个C++程序开发一种新的语言。

问题是，这段代码不会在gcc上编译，我完全不知道为什么。

意图的行为作为一种游戏遵循一组规则：

游戏被表示为一个二维数组，随机填充的二进制单元，每个活的或死的。

每个“回合”的游戏，细胞生存或死亡的基础上的规则子集。

如果一个牢房有4个或4个以上的活邻居，它就会因过度拥挤而死亡。

如果一个牢房有一个或更少的活邻居，它就会孤独而死。

如果一个死掉的细胞正好有三个邻居，它就会像殖民地一样活过来。

为了确定邻居，板的每一面都被认为是相邻的。因此，右侧与左侧相邻，反之亦然。同样适用于顶部和底部，也适用于角落。

例如:有8个邻居，上面是n- 1，在同一行是，下面是1,1和1。

运行，直到板中没有任何更改或用户指定的最大周期已经完成。

其中最令人困惑的元素可能是，我选择以最简单的方式表示它，方法是通过N+2数组将N×N数组镜像到一个N+2数组中，并在周围的"shell“中填充表示内部相对邻居的”幽灵值“。

如果你能帮我把这个从一楼弄出去，我将不胜感激。去看更多的书我走了。

#include "Life.h"
#include <stdio.h>      /* printf, scanf, puts, NULL */
#include <stdlib.h>     /* rand */
#include <time.h>       /* time */
#include<iostream>
#include<fstream>
using namespace std;
/*
 * Main handles the first steps, collecting user input. It creates the initial board, then passes it for further manipulation.
 */
int main(){
    time_t start;
    time(&start);
    int rows;
    cout << "Please input the row number \n";
    cin >> rows;
    rows += 2;
    int maxCycles;
    cout << "Please input Maximum cycles \n";
    cin >> maxCycles;
    int** board = new int*[rows];
    for(int i = 0; i < rows; ++i){
        board[i] = new int[rows];
    }
    initBoard(board, rows);
    playGame(board, rows, maxCycles);
    time_t end;
    cout << "Runtime:" << end-start << "\n";

    return 0;
}

/*
 * Randomizes the chance of a cell to be alive in the initial cycle. After values are initialized, passes board to set ghost values, i.e., the surrounding opposite side neighbors.
 */
void initBoard(int** board, int rows){
    for(int i = 1; i < rows-1; ++i){
        for(int j = 1; j < rows-1; ++j){
            if(rand()%4 == 0){
                board[i][j] = 1;
            }else{
                board[i][j] = 0;
            }
        }
    }
    setGhosts(board, rows);
}

/*
 * Sets the ghost values framing the functioning game board
 */
void setGhosts(int** board, int rows){
    for(int i = 1; i < rows-1; ++i){
        board[0][i] = board[rows-2][i];
        board[rows-1][i] = board[1][i];
        board[i][0] = board[i][rows-2];
        board[i][rows-1] = board[i][1];
    }

    //Sets corner values
    board[0][0] = board[rows-2][rows-2];
    board[rows-1][rows-1] = board[1][1];
    board[0][rows-1] = board[rows-2][1];
    board[rows-1][0] = board[1][rows-2];
}

//Runs up to maxCycles cycles of the game, with each cycle altering the value of board.
void playGame(int** board, int rows, int maxCycles){
    int boolean = 1;
    for(int k = 0; k < maxCycles; ++k){
        //initialize temp array
        int** temp = new int*[rows];
        for(int i = 0; i < rows; ++i){
            temp[i] = new int[rows];
        }
        //Begin game
        for(int i = 1; i < rows-1;++i){
            for(int j = 1; j < rows; ++j){
                //check live neighbors
                int count = neighbors(board, i, j);
                if(board[i][j] == 1){//If alive, check if it stays alive
                    if(count < 4 || count > 1){
                        temp[i][j] = 1;
                    }else{
                        temp[i][j] = 0;
                        boolean = 0;
                    }
                }else if(board[i][j] == 0){//If dead, check if it stays dead
                    if(count == 3){
                        temp[i][j] = 1;
                        boolean = 0;
                    }else{
                        temp[i][j] = 0;
                    }
                }
            }
        }
        setGhosts(temp, rows);
        board = temp;
        if(boolean == 1) break;//If there is no change in the board across a cycle, the game is over
    }
    printBoard(board, rows);
}

//Returns the number of living neighbors to the given cell[i][j]
int neighbors(int** board, int i, int j){
    int count = 0;
    if(board[i-1][j-1] == 1){ ++count;}
    if(board[i-1][j] == 1){ ++count;}
    if(board[i-1][j+1] == 1){ ++count;}
    if(board[i][j-1] == 1){ ++count;}
    if(board[i][j+1] == 1){ ++count;}
    if(board[i+1][j-1] == 1){ ++count;}
    if(board[i+1][j] == 1){ ++count;}
    if(board[i+1][j+1] == 1){ ++count;}
    return count;
}

void printBoard(int** board, int rows){
    for(int i=1; i< rows-1; i++){
        for(int j=1; j< rows-1; j++){
            cout << board[i][j]  << "  ";
        }
        cout << endl;
    }
}

Answer 1

从g++输出的观测误差

g++ -c -Wall -ansi -O3 -std=c++11 foo.cc
foo.cc: In function 'int main()':
foo.cc:51:26: error: 'initBoard' was not declared in this scope
     initBoard(board, rows);
                          ^
foo.cc:52:36: error: 'playGame' was not declared in this scope
     playGame(board, rows, maxCycles);
                                    ^
foo.cc: In function 'void initBoard(int**, int)':
foo.cc:72:26: error: 'setGhosts' was not declared in this scope
     setGhosts(board, rows);
                          ^
foo.cc: In function 'void playGame(int**, int, int)':
foo.cc:106:50: error: 'neighbors' was not declared in this scope
                 int count = neighbors(board, i, j);
                                                  ^
foo.cc:128:27: error: 'printBoard' was not declared in this scope
     printBoard(board, rows);
                           ^
make: *** [foo.o] Error 1

如何修复它

您必须转发声明所有函数，以便编译器在调用它们时了解它们。在调用这些函数的方式上，您有一个顺序依赖关系。将函数的顺序更改为类似于int main()位于文件底部的顺序。

1. void setGhosts(int** board, int rows)
2. void initBoard(int** board, int rows)
3. int neighbors(int** board, int i, int j)
4. void printBoard(int** board, int rows)
5. void playGame(int** board, int rows, int maxCycles)
6. int main()

您也有一些不必要的包含，如#include "Life.h"和#include <stdio.h>。另一个C包括应该使用C++格式，即不是#include <stdlib.h>，它应该是#include <cstdlib>，而不是#include <math.h>，它应该是#include <cmath>。

最后，在未初始化end的情况下，您在end的末尾遇到了一个问题。一旦你把所有其他问题都解决了，你就会看到它。