数据结构与算法-----堆栈篇

堆栈

1.基本特征：后进先出

2.基本操作：压入(push)，弹出(pop)

3.实现要点：初始化空间、栈顶指针、判空判满

实践：使用C++语言实现堆栈类，进行示例演示并且根据此堆栈类实现进制的转换。

#include <iostream>
using namespace std;
class Stack {
public:
    // 构造函数中分配内存空间
    Stack (size_t size = 10) :
        m_data (new int[size]), m_size (size),
        m_top (0) {}
    // 析构函数中释放内存空间
    ~Stack (void) {
        if (m_data) {
            delete[] m_data;
            m_data = NULL;
        }
    }
    // 压入
    void push (int data) {
        if (full ())
            throw OverFlow ();
        m_data[m_top++] = data;
    }
    // 弹出
    int pop (void) {
        if (empty ())
            throw UnderFlow ();
        return m_data[--m_top];
    }
    // 判空
    bool empty (void) {
        return ! m_top;
    }
    // 判满
    bool full (void) {
        return m_top >= m_size;
    }
private:
    // 上溢异常
    class OverFlow : public exception {
    public:
        const char* what (void) const throw () {
            return "堆栈上溢！";
        }
    };
    // 下溢异常
    class UnderFlow : public exception {
    public:
        const char* what (void) const throw () {
            return "堆栈下溢！";
        }
    };
    int*   m_data; // 数组
    size_t m_size; // 容量
    size_t m_top;  // 栈顶
};
void printb (unsigned int numb, int base) {
    Stack stack (100);
    do {
        stack.push (numb % base);
    }   while (numb /= base);
    while (! stack.empty ()) {
        int digit = stack.pop ();
        if (digit < 10)
            cout << digit;
        else
            cout << char (‘A‘ + (digit - 10));
    }
    cout << endl;
}
int main (void) {
    try {
        Stack stack（20）;
        for (int i = 0; ! stack.full (); i++)
            stack.push (i);
        while (! stack.empty ())
            cout << stack.pop () << "  ";
        cout << endl;
        cout << "整数：" << flush;
        int numb;
        cin >> numb;
        cout << "进制：" << flush;
        int base;
        cin >> base;
        cout << "结果：";
        printb (numb, base);
    }
    catch (exception& ex) {
        cout << ex.what () << endl;
        return -1;
    }
    return 0;
}

输出结果：