链表的C#代码实现

题目：　　1.在尾部增加元素

　　　　　2. 删除值为value的元素

　　　　　3.反转链表

思路：

增加和反转都没啥说的，就删除的时候需要考虑到的情况比较多，直接上代码，回头再分析

  1     class LinkNode<T>
  2     {
  3         public LinkNode<T> Next { get; set; }
  4         public T Value { get; set; }
  5 
  6         public LinkNode<T> AddNodeToEnd(T value, LinkNode<T> head)
  7         {
  8             if (value != null)
  9             {
 10                 if (head == null)
 11                 {
 12                     head = new LinkNode<T>();
 13                     head.Value = value;
 14                     head.Next = null;
 15                 }
 16                 else
 17                 {
 18                     LinkNode<T> temp = head;
 19                     while (temp != null)
 20                     {
 21                         if (temp.Next == null)
 22                         {
 23                             temp.Next = new LinkNode<T>();
 24                             temp.Next.Value = value;
 25                             break;
 26                         }
 27                         temp = temp.Next;
 28                     }
 29                 }
 30             }
 31             return head;
 32         }
 33 
 34         //public LinkNode<T> Remove(T value, LinkNode<T> head)
 35         //{
 36         //    LinkNode<T> pre = null;
 37         //    LinkNode<T> now = null;
 38         //    if (value != null)
 39         //    {
 40         //        if (head != null)
 41         //        {
 42         //            pre = head;
 43         //            if (head.Value.Equals(value) && head.Next == null)
 44         //            {
 45         //                head = null;
 46         //                return head;
 47         //            }
 48         //            if (head.Next != null) { now = head.Next; }
 49         //            while (now != null)
 50         //            {
 51         //                if (head.Value.Equals(value))
 52         //                {
 53         //                    head.Next = null;
 54         //                    head = now;
 55         //                    pre = head;
 56         //                    if (head.Next != null) { now = head.Next; }
 57         //                    else now = head; 
 58         //                }
 59         //                if (now.Value.Equals(value))
 60         //                {
 61         //                    if (now.Next != null)
 62         //                    {
 63         //                        LinkNode<T> next = now.Next;
 64         //                        pre.Next = next;
 65         //                        now.Next = null;
 66         //                        pre = pre.Next;
 67         //                        now = pre.Next;
 68         //                        continue;
 69         //                    }
 70         //                    else
 71         //                    {
 72         //                        if (pre == now) return null;
 73         //                        pre.Next = null;
 74         //                        break;
 75         //                    }
 76         //                }
 77         //                pre = now;
 78         //                now = now.Next;
 79 
 80         //            }
 81         //        }
 82         //    }
 83         //    return head;
 84         //}
 85 
 86         public LinkNode<T> Remove(T value, LinkNode<T> head)
 87         {
 88             LinkNode<T> pre = null;
 89             LinkNode<T> now = null;
 90             if (value != null)
 91             {
 92                 if (head != null)
 93                 {
 94                     //如果只有一个元素head
 95                     if (head.Next == null)
 96                     {
 97                         //如果head就是要找的那个
 98                         if (head.Value.Equals(value))
 99                         {
100                             head = null;
101                         }
102                     }   
103                     //如果有两个以上的元素                
104                     else
105                     {
106                         pre = head;
107                         now = head.Next;
108                         while (now != null)
109                         {
110                             if (pre.Value.Equals(value))
111                             {
112                                 //如果第一个就遇到了value
113                                 if (pre == head)
114                                 {
115                                     head = head.Next;
116                                     pre = head;
117                                     if (pre == null) break;
118                                     if (pre.Next != null) now = pre.Next;
119                                     else now = pre;
120                                 }
121                                 else
122                                 {                                    
123                                     if (now.Next != null)
124                                     {
125                                         pre.Next = now.Next;
126                                         now = now.Next;
127                                     }
128                                     else break;
129                                 }
130                             }
131                             else
132                             {
133                                 if (now.Value.Equals(value))
134                                 {
135                                     if (now.Next != null && pre == head)
136                                     {
137                                         pre.Next = now.Next;
138                                         now = pre.Next;
139                                         continue;                                     
140                                     }
141                                     else if (now.Next != null)
142                                     {
143                                         now = now.Next;
144                                     }                                    
145                                     else pre.Next = null;
146                                 }
147                                 if (now.Next != null)
148                                 {
149                                     now = now.Next;
150                                     pre = pre.Next;
151                                 }
152                                 else break;
153                             }
154                                                       
155                         }
156                     }                   
157                 }
158             }
159             return head;
160         }
161         public LinkNode<T> Revert(LinkNode<T> head)
162         {
163             LinkNode<T> pre = null;
164             LinkNode<T> now = null;
165             LinkNode<T> next = null;
166 
167             if (head != null && head.Next != null)
168             {
169                 pre = head;
170                 now = head.Next;
171                 while (now != null)
172                 {
173                     if (pre == head && now.Next == null)
174                     {
175                         pre = head;
176                         now.Next = pre;
177                         head = now;
178                         pre.Next = null;
179                         return head;
180                     }
181                     else
182                     {
183                         if (pre == head)
184                         {
185                             pre.Next = null;
186                         }
187                         next = now.Next;
188                         now.Next = pre;
189                         pre = now;
190                         now = next;
191                     }
192                 }
193                 head = pre;
194             }
195             return head;
196         }
197     }

主函数：

 1  static void Main(string[] args)
 2         {
 3             LinkNode<string> s = new LinkNode<string>();
 4             s = s.AddNodeToEnd("1", null);
 5             s = s.AddNodeToEnd("2", s);
 6             s = s.AddNodeToEnd("3", s);
 7             s = s.AddNodeToEnd("5", s);
 8             s = s.AddNodeToEnd("1", s);
 9             s = s.Remove("3", s);
10             s = s.Revert(s);
11             Console.ReadKey();
12         }

posted @ 2017-11-09 18:26 美美美少女阅读(839) 评论(0) 编辑收藏举报

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链表的C#代码实现

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