手写单链表（基础）

手写了一个单链表，实现了一些简单的功能。

  1 #pragma once
  2 
  3 using namespace std;
  4 
  5 class Node
  6 {
  7 public:
  8     Node* next;
  9     int data;
 10 };
 11 
 12 class List
 13 {
 14 private:
 15     Node* head;
 16     int length;
 17 
 18 public:
 19     List();
 20     int size();
 21     bool empty();
 22     void push_front(int num);
 23     void push_back(int num);
 24     bool insert(int pos, int num);
 25     bool erase(int pos);
 26     bool find(int num);
 27     void clear();
 28     void show();
 29 };
 30 
 31 List::List()
 32 {
 33     head = new Node;
 34     head->next = nullptr;
 35     head->data = 0;
 36     length = 0;
 37 }
 38 
 39 int List::size()
 40 {
 41     return length;
 42 }
 43 
 44 bool List::empty()
 45 {
 46     if (length == 0) return true;
 47     else return false;
 48 }
 49 
 50 void List::push_front(int num)
 51 {
 52     Node* first = head->next;
 53     Node* pushNode = new Node;
 54     pushNode->data = num;
 55     pushNode->next = first;
 56     head->next = pushNode;
 57     length++;
 58 }
 59 
 60 void List::push_back(int num)
 61 {
 62     Node* temp = head;
 63     while (temp->next != nullptr)
 64     {
 65         temp = temp->next;
 66     }
 67     Node* pushNode = new Node;
 68     pushNode->data = num;
 69     pushNode->next = nullptr;
 70     temp->next = pushNode;
 71     length++;
 72 }
 73 
 74 bool List::insert(int pos, int num)
 75 {
 76     Node* temp = head;
 77     int i = 0;
 78     if (pos < 0 || pos > length) return false;
 79     while (i < pos && temp->next != nullptr)
 80     {
 81         i++;
 82         temp = temp->next;
 83     }
 84     Node* pushNode = new Node;
 85     pushNode->data = num;
 86     pushNode->next = temp->next;
 87     temp->next = pushNode;
 88     length++;
 89     return true;
 90 }
 91 
 92 bool List::erase(int pos)
 93 {
 94     Node* temp = head;
 95     int i = 0;
 96     if (pos <= 0 || pos > length || length == 0) return false;
 97     while (i < pos - 1 && temp->next != nullptr)
 98     {
 99         i++;
100         temp = temp->next;
101     }
102     Node* q = temp->next;
103     temp->next = q->next;
104     free(q);
105     length--;
106     return true;
107 }
108 
109 bool List::find(int num)
110 {
111     Node* temp = head->next;
112     int i = 1;
113     while (temp != nullptr && temp->data != num)
114     {
115         temp = temp->next;
116         i++;
117     }
118     if (temp == nullptr)
119         return -1;
120     else 
121         return i;
122 }
123 
124 void List::clear()
125 {
126     Node* nextNode = head->next;
127     while (nextNode != nullptr)
128     {
129         Node* temp = nextNode->next;
130         delete nextNode;
131         nextNode = temp;
132     }
133     length = 0;
134     head->next = nullptr;
135 }
136 
137 void List::show()
138 {
139     if (length == 0) return;
140     else
141     {
142         Node* temp = head->next;
143         while (temp->next != nullptr)
144         {
145             cout << temp->data << " ";
146             temp = temp->next;
147         }
148         cout << temp->data << endl;
149     }
150 }

 

posted @ 2020-09-15 11:09  章楠雨  阅读(215)  评论(0)  编辑  收藏  举报