常用数据结构之栈

使用数组和链表实现两种栈结构

class StackBase {
public:
    typedef int Elemtype;
    virtual Elemtype top()=0;
    virtual void push(Elemtype)=0;
    virtual void pop()=0;
    virtual int size()=0;
    virtual bool empty()=0;
};
class ArrStack: public StackBase {
public:
    ArrStack() {
        maxSize = 3;
        increment = 2;
        curnums = 0;
        baseE = new Elemtype[maxSize];
        topE = baseE;
    }
    ~ArrStack() {
        delete[] baseE;
    }
    Elemtype top() {
        if (baseE == topE)
            return -1;
        return *(topE - 1);
    }
    int size() {
        return curnums;
    }
    void push(Elemtype e) {
        if (curnums >= maxSize) {
            Elemtype *temp = new Elemtype[maxSize + increment];
            memcpy(temp, baseE, curnums * sizeof(Elemtype));
            delete[] baseE;
            baseE = temp;
//            for (int i = 0; i < curnums; i++)
//                cout << baseE[i] << " ";
//            cout << endl;
            topE = baseE + curnums;
            maxSize += increment;
        }
        *topE++ = e;
        curnums++;
    }
    void pop() {
        if (baseE == topE)
            return;
        topE--;
        curnums--;
    }
    bool empty() {
        if (curnums == 0)
            return true;
        else if (curnums > 0)
            return false;
        return false;
    }
private:
    int maxSize;
    int curnums;
    int increment;
    Elemtype *baseE;
    Elemtype *topE;

public:
    static void test() {
        ArrStack a;
        a.push(1);
        a.push(2);
        a.push(3);
        a.push(4);
        cout << "size: " << a.size() << endl;
        while (!a.empty()) {
            cout << a.top() << " ";
            a.pop();
        }
        cout << endl;
        cout << "size: " << a.size() << endl;
    }
};
class ListStack: public StackBase {
public:
    struct ListNode {
        Elemtype val;
        ListNode *next;
        ListNode(Elemtype e) :
                val(e), next(NULL) {
        }
    };
    ListStack() {
        topE = NULL;
        curnums = 0;
    }
    ~ListStack() {

    }
    Elemtype top() {
        if (topE == NULL)
            return -1;
        return topE->val;
    }
    void push(Elemtype e) {
        ListNode *tem = new ListNode(e);
        tem->next = topE;
        topE = tem;
        curnums++;
    }
    void pop() {
        if (curnums == 0)
            return;
        ListNode *tem = topE;
        topE = topE->next;
        delete tem;
        curnums--;
    }
    int size() {
        return curnums;
    }
    bool empty() {
        if (curnums == 0)
            return true;
        else if (curnums > 0)
            return false;
        return false;
    }
private:
    int curnums;
    ListNode *topE;
public:
    static void test() {
        ListStack a;
        a.push(1);
        a.push(2);
        a.push(3);
        a.push(4);
        cout << "size: " << a.size() << endl;
        while (!a.empty()) {
            cout << a.top() << " ";
            a.pop();
        }
        cout << endl;
        cout << "size: " << a.size() << endl;
    }
};