所有.我有一个类定义如下:
class Board {
int columns, rows;
bool board[10][10];
public:
Board(int, int);
void nextFrame();
void printFrame();
};
我的void nextFrame()不断给我[rows] [columns]的错误,因为“”’不能在它们的两个常量表达式中”.我怎样才能重新定义它以使其有效?我理解错误.函数的定义如下,并且错误发生在以下代码示例的第3行.
void Board::nextFrame() {
int numSurrounding = 0;
bool tempBoard[rows][columns];
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < columns; j++)
{
if ((i + 1) < rows && board[i + 1][j] == true)
{
numSurrounding++;
}
if ((i - 1) >= 0 && board[i - 1][j] == true)
{
numSurrounding++;
}
if ((j + 1) < columns && board[i][j + 1] == true)
{
numSurrounding++;
}
if ((j - 1) >= 0 && board[i][j - 1] == true)
{
numSurrounding++;
}
if ((i + 1) < rows && (j + 1) < columns && board[i + 1][j + 1] == true)
{
numSurrounding++;
}
if ((i + 1) < rows && (j - 1) >= 0 && board[i + 1][j - 1] == true)
{
numSurrounding++;
}
if ((i - 1) >= 0 && (j + 1) < columns && board[i - 1][j + 1] == true)
{
numSurrounding++;
}
if ((i - 1) >= 0 && (j - 1) >= 0 && board[i - 1][j - 1] == true)
{
numSurrounding++;
}
if (numSurrounding < 2 || numSurrounding > 3)
{
tempBoard[i][j] = false;
}
else if (numSurrounding == 2)
{
tempBoard[i][j] = board[i][j];
}
else if (numSurrounding == 3)
{
tempBoard[i][j] = true;
}
numSurrounding = 0;
}
}
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < columns; j++)
{
board[i][j] = tempBoard[i][j];
}
}
}
最佳答案 您需要使用STL中的集合.
这是一个嵌套向量来获得你的董事会的例子:
#include <vector>
#include <iostream>
using namespace std;
class Board {
int columns, rows;
vector<vector<bool>> board;
public:
Board(int x, int y) : board(vector<vector<bool>>(x, vector<bool>(y))) {
}
void nextFrame() {
// Fill in
}
void printFrame() {
// Fill in
}
size_t xdim() {
return board.size();
}
size_t ydim() {
if (board.size() == 0) {
return 0;
}
return board.at(0).size();
}
};
int main() {
Board b(10, 20);
cout << "Made the board" << endl;
cout << "X: " << b.xdim() << endl;
cout << "Y: " << b.ydim() << endl;
}
您可以了解board(vector< vector< bool>>(x,vector< bool>(y)))here和here的成员初始化语法.