我一直在犯这个错误，这让我越来越沮丧，请帮助我

Question

第1034行：Char 9:运行时错误：引用绑定到'std:：vector'类型的空指针

void gameOfLife(vector<vector<int>>& board) {
   vector<vector<int>> newBoard;
    for(int i = 0; i < board.size(); i++){
        for(int j = 0; j < board[i].size(); j++){
            if(board[i][j] == 0 && neibSum(board,i,j) == 3)
                newBoard[i][j] = 1;
            else if(board[i][j] == 1 && neibSum(board,i,j) > 3)
                newBoard[i][j] = 0;
            else if(board[i][j] == 1 && neibSum(board,i,j) < 2)
                newBoard[i][j] = 0;
            else
                newBoard[i][j] = 1;
        }
    }
    for(int i = 0; i < board.size(); i++){
        for(int j = 0; j < board[i].size(); j++){
            cout << newBoard[i][j] << " ";
        }
        cout << endl;
    }
    
}

Answer 1

你可以在一行中初始化你的电路板

#include <vector>

// two constants for you board size
// stl containers mostly accept std::size_t for their sizes
constexpr std::size_t board_height_v = 25;
constexpr std::size_t board_width_v = 80;

enum class cell
{
    dead,
    alive
};

int main()
{
    // I made a cell enum so you can more easily spot where the initial cell value is set.
    // now lets initialize the board to the correct size
    std::vector<std::vector<cell>> newBoard(board_height_v, std::vector<cell>(board_width_v,cell::dead));

    return 1;
}

Answer 2

变量“newboard”是一个大小为0的向量。在：

newBoard[i][j] = 1;

您正在尝试访问未分配的内存。您需要首先分配内存（例如使用resize）。

   vector<vector<int>> newBoard;
    newBoard.resize(board.size());
    for(int i = 0; i < board.size(); i++){
        newBoard[i].resize(board[i].size());
        for(int j = 0; j < board[i].size(); j++){
...

编辑：另外，你可以使用。at（）函数，而不是[]来访问向量元素：newBoard。在（我）。在（j）中包含边界检查。它不会解决您的问题，但会让您更容易理解错误消息。