小编Ser*_* Qi的帖子

我刚学习了C++指针和删除指针.我自己尝试了这个代码

# include<iostream>

using namespace std;

int main(){
    int num = 10;
    int *p = new int;

    p = &num;
    cout << *p << endl;
    delete p;
    cout << num << endl;
    return 0;
}

删除指针后p,我无法打印值num.但如果我p在程序的最后删除,cout << num << endl;会给我10.任何人都知道我在哪里运行？

当我运行构建完美迷宫的代码时出现此错误。这是代码：

   def walk(self, s, x, y):

        neighboor = [(x + 1, y), (x - 1, y), (x, y + 1), (x, y - 1)]

        if s.size() == self.size**2: return

        else:

            while True:
                new = choice(neighboor)
                if self.is_valid(new[0], new[1]): break

            while self.maze[new[0]][new[1]].getVisit():

                if len(neighboor) != 0: new = choice(neighboor.remove(new))
                else:
                    temp = s.pop(s)
                    self.walk(s, temp[0], temp[1])

            #print(new)

            self.maze[new[0]][new[1]].changeVisit()
            if new == neighboor[1]:
                self.maze[x][y].changeNorth()
                self.maze[new[0]][new[1]].changeSouth()
            elif new == neighboor[0]:
                self.maze[x][y].changeSouth()
                self.maze[new[0]][new[1]].changeNorth()
            elif new == neighboor[2]:
                self.maze[x][y].changeEast()
                self.maze[new[0]][new[1]].changeWest()
            elif new == neighboor[3]:
                self.maze[x][y].changeWest() …