算法复习（6）链表实现的队列

　　使用链表实现的队列，先进先初，压入弹出判空。

  1 // 基于链表的队列
  2 #include <iostream>
  3 using namespace std;
  4 template <typename T>
  5 class Queue
  6 {
  7 public:
  8     //在构造过程中初始化为空队列
  9     Queue(void) : m_rear (NULL), m_front (NULL) {}
 10     //在析构过程中销毁剩余节点
 11     ~Queue(void)
 12     {   
 13         for (Node* next; m_front; m_front = next)
 14         {   
 15             next = m_front->m_next;
 16             delete m_front;
 17         }   
 18     }   
 19     // 压入
 20     void push(T data)
 21     {   
 22         Node* node = new Node(data);
 23         if (m_rear)
 24             m_rear->m_next = node;
 25         else
 26             m_front = node;
 27         m_rear = node;
 28     }
 29     // 弹出
 30     T pop(void)
 31     {
 32         if (empty())
 33             throw UnderFlow();
 34         T data = m_front->m_data;
 35         Node* next = m_front->m_next;
 36         delete m_front;
 37         if (!(m_front = next))
 38             m_rear = NULL;
 39         return data;
 40     }
 41     // 判空
 42     bool empty(void)
 43     {
 44         return !m_front && !m_rear;
 45     }
 46 private:
 47     //下溢异常
 48     class UnderFlow : public exception
 49     {
 50         const char* what(void) const throw ()
 51         {
 52             return "队列下溢";
 53         }
 54     };
 55     //节点
 56     class Node
 57     {
 58     public:
 59         Node(T data, Node* next = NULL) :
 60             m_data (data), m_next (next) {}
 61         T m_data;       //数据
 62         Node* m_next;   //后指针
 63     };
 64     Node* m_rear;
 65     Node* m_front;
 66 };
 67 
 68 // 测试基本类型
 69 void test_int(void)
 70 {
 71         Queue<int> queue;
 72         for (int i = 0; i < 5; ++i)
 73             queue.push(i);
 74         while (!queue.empty())
 75             cout << queue.pop() << endl;
 76         cout << endl;
 77 }
 78 
 79 // 测试类
 80 struct List
 81 {
 82     List(string name, int price) : m_name (name),
 83         m_price (price) {}
 84     string m_name;
 85     int m_price;
 86 };
 87 void test_class(void)
 88 {
 89     List l1("小米", 1999);
 90     List l2("iphone 5s", 5288);
 91     Queue<List> queue;
 92     queue.push(l1);
 93     queue.push(l2);
 94 //    cout << queue.pop().m_name << queue.pop().m_price << endl;
 95 //    cout << queue.pop().m_price << queue.pop().m_name << endl;
 96     List l = queue.pop();
 97     cout << l.m_name << "手机, 价格: " << l.m_price
 98         << "元." << endl;
 99 }
100 
101 //测试string类
102 void test_string(void)
103 {
104     string s1 = "C";
105     string s2 = "C++";
106     string s3 = "c#";
107     string s4 = "java";
108     Queue<string> queue;
109     queue.push(s1);
110     queue.push(s3);
111     queue.push(s3);
112     queue.push(s4);
113     cout << queue.pop() << endl;
114     cout << queue.pop() << endl;
115     cout << queue.pop() << endl;
116     cout << queue.pop() << endl;
117     cout << queue.pop() << endl;
118 }
119 int main(void)
120 {
121     try
122     {
123         //test_int();
124         //test_string();
125         test_class();
126     }
127     catch (exception& ex)
128     {
129         cout << ex.what() << endl;
130         return -1;
131     }
132     return 0;
133 }
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posted on 2013-11-27 23:33  4IT  阅读(195)  评论(0)  编辑  收藏  举报

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