C++

Forum

 
Double linked list : insertion stops after entering third value

yepMe (87)
Hi All,

I am writing a double linked list , but my program is giving me a weird problem, for the insertion if I enter the first node it's working fine and also the second node , but if i enter 3rd node the screen just stops there neither vanishes nor prints the prompt for entering 4th node .below is my code .

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
 
  #include<iostream>

using namespace std;

struct node
{      node * prv;
       int num;
       node * next;
       
};

class link_list
{
      node * head;
      node * list;
      public :
             
      link_list()
      {
                 head =NULL;
                 list = NULL;
                 
      }
      
             void insert();
             //void del_at_pos();
             //void reverse_list();
             void print_list();
};

void link_list :: insert()
{
     char ch1;
     int no;
     do{
         cout <<"add the node u wish to add?"<<endl;
         cin >> no;
     if(head==NULL)
     {
       head = new node;
       list= head;
       head->num = no;
       head->next=NULL;
       head->prv=NULL;
       
     }
     else
     {
         node * newNode;
         list=head;
         while(list->next!=NULL)
         {
            list->next=list;
         }
         newNode = new node;
         newNode->num=no;
         newNode->prv=list;
         list->next = newNode;
         newNode->next=NULL;
     }
     cout <<"do u wish to add another node?" << endl;
     cin >> ch1;
     }while(ch1=='y'||ch1=='Y');
}

void link_list :: print_list()
{
     int count=0;
     if(head==NULL)
     {
        cout << "List is Empty!!!" << endl;
     }
     else
     {
         list=head;
         while(list!=NULL)
         {
           count++;
           cout << count << "    " << list->num <<endl;
           list =list->next;
         }
     }
 }
int main()
{
     char ch;
    link_list ll;
    do
    {
      
      cout<< "select anyone of the following :" << endl;
      cout <<"press 1 for insertion :" << endl;
      cout <<"press 2 for deletion :"<<endl;
      cout <<"press 3 for reverse :" << endl;
      cout <<"press 4 for print :"<<endl;
      int i;
      cin >> i;
      switch (i)
      {
      case 1 :
           ll.insert();
           break;
     /* case 2 :
           ll.del_at_pos();
           break;
      case 3 :
           ll.reverse_list();
           break;*/
      case 4 :
           ll.print_list();
           break;
      default :
              cout <<"oops wrong choice!!!"<<endl;
      }
      cout << "do you want to make another choice ?" << endl;
     
      cin >> ch;
    }while(ch=='y'||ch=='Y');
    system("pause");
    return 0;
}
yepMe (87)
someone please help!!!
cire (8284)
1
2
3
4
 
            while (list->next != NULL)
            {
                list->next = list;
            }


What do you suppose this does?
yepMe (87)
oops my mistake :(.. found the problem...
Last edited on
Topic archived. No new replies allowed.