Question

我把它全部取下以便打印出来后，我很难重新填充堆栈。我正在使用节点实现，所以我认为这个事实让我感到困惑。任何建议将不胜感激，谢谢。

这是我原来的堆栈:: print（）



// Function to print Gumball info field (color and counter)
void Stack::print()
{
    Node *p;
    Type x;

    while(top != NULL) {
        p = top;
        x = p -> getinfo();
        cout << " " << x.color << " " << " " << x.counter << endl << endl;
        top = p -> getnext();
    } 

    return;
}


This is my stack with my attempt to loop and store in temp. It compiles but still is not working as suppose to


void Stack::print()
{
    Node *p,*q;
    Type x,x_temp;

    while(top != NULL) {
        p = top;
        x = p -> getinfo();
        cout << " " << x.color << " " << " " << x.counter << endl << endl;
        x_temp = x;
        q = top;
        top = p -> getnext();
    }

    while(top != NULL) {
        q -> setinfo(x_temp);
        q -> setnext(top);
        top = q;
    }
    return;
}

// Function to print Gumball info field (color and counter) void Stack::print() { Node *p; Type x; while(top != NULL) { p = top; x = p -> getinfo(); cout << " " << x.color << " " << " " << x.counter << endl << endl; top = p -> getnext(); } return; }

Answer 1

如果要打印堆栈的内容，然后以相同的顺序将所有值推回，我建议在打印后将值推送到不同的堆栈。然后，一旦原始堆栈为空，将第二个堆栈中的所有值弹回原始堆栈。

Answer 2

Stack::print显示了您的堆栈的当前“snapshop”，因此它无法修改任何Stack的成员变量。没有必要对堆栈进行“备份”并恢复它。你只需要以不会打扰堆栈的方式走下堆栈。

不是让top成员变量向下遍历堆栈，而是将本地Node指针初始化为与top相同，并使本地指针沿堆栈向下移动。

换句话说，top在print成员函数中应该是只读的（不可变的）。要强制成员函数不能修改任何成员变量，可以通过在成员函数声明的末尾添加const关键字使成员函数不可变。

示例：

// Const member function enforces that the Stack remain unmodified
void Stack::print() const
{
    Node *p = top; // Make p initially point to the top of the stack
    Type x;

    while(p != NULL) {
        x = p -> getinfo();
        cout << " " << x.color << " " << " " << x.counter << endl << endl;
        p = p->getNext(); // Make p walk down the stack to the next Node.
    } 
}

使用节点实现重新填充堆栈

2 个答案: