Write down a C Program to insert in beginning & end, delete a node in beginning & end, Traverse for the Doubly Linked List and also modify a specified node for the Doubly Linked List using Global start variable & call by reference & by using the Switch Case.

Write down a C Program to insert in beginning & end, delete a node in beginning & end, Traverse for the Doubly Linked List and also modify a specified node for the Doubly Linked List using Global start variable & call by reference & by using the Switch Case.

1. #include <stdio.h>
2. #include <stdlib.h>
3. #include <malloc.h>
4. struct node 
5. {
6. struct node *prev;
7. int data;
8. struct node *next;
9. };
10. struct node *start=NULL;
11. void create_nodebegining(int);
12. void create_nodeend(int);
13. void delete_nodebegining();
14. void delete_nodeend();
15. void modify(int,int);
16. void traverse();
17. int main()
18. {
19. int data,i,n,ch,data1;
20. printf("\n Enter The Value of data to be Entered:\n");
21. scanf("%d",&n);
22. for(i=0;i<n;i++)
23. {
24. printf("\n Enter The Value Should be Enter In Data of Node:\n");
25. scanf("%d",&data);
26. create_nodeend(data);
27. }
28. printf("\n Please Enter Your Choise \n ");
29. printf("\n Press 1 for Insert in Beginning \n Press 2 for Insert in end \n Press 3 Delete in Beginning \n Press 4 for delete in end \n Press 5 for modify \n press 6 for traverse \n");
30. scanf("%d",&ch);
31. switch(ch)
32. {
33. case 1:
34. printf("\n Enter The Value For Node Data:\n");
35. scanf("%d",&data);
36. create_nodebegining(data);
37. break;
38. case 2:
39. printf("\n Enter The Value For Node Data:\n");
40. scanf("%d",&data);
41. create_nodeend(data);
42. break;
43. case 3:
44. delete_nodebegining();
45. break;
46. case 4:
47. delete_nodeend();
48. break;
49. case 5:
50. printf("\n Enter The Data To be Modified:\n");
51. scanf("%d",&data1);
52. printf("\n Enter The Data Modified:\n");
53. scanf("%d",&data);
54. modify(data1,data);
55. break;
56. case 6:
57. traverse();
58. break;
60. }
61. traverse();
62. }
63. void create_nodeend(int x)
64. {
65. struct node *t,*t1;
66. t=(struct node*)malloc(sizeof(struct node));
67. t->prev=NULL;
68. t->data=x;
69. t->next=NULL;
70. if(start==NULL)
71. {
72. start=t;
73. }
74. else
75. {
76. t1=start;
77. while(t1->next!=NULL)
78. {
79. t1=t1->next;
80. }
81. t1->next=t;
82. t->prev=t1;
83. }
84. }
85. void create_nodebegining(int x)
86. {
87. struct node *t,*t1;
88. t1=start;
89. t=(struct node*)malloc(sizeof(struct node));
90. t->prev=NULL;
91. t->data=x;
92. t->next=t1;
93. t1->prev=t;
94. start=t;
95. traverse();
96. }
97. void delete_nodeend()
98. {
99. struct node *t,*t1;
100. t=start;
101. while(t->next!=NULL)
102. {
103. t1=t;
104. t=t->next;
105. }
106. free(t);
107. t1->next=NULL;
108. traverse();
109. }
110. void delete_nodebegining()
111. {
112. struct node *t,*t1;
113. t1=start;
114. start=t1->next;
115. start->prev=NULL;
116. traverse();
117. }
118. void modify(int x,int y)
119. {
120. struct node *t;
121. t=start;
122. while(t->data!=x)
123. {
124. t=t->next;
125. }
126. t->data=y;
127. traverse();
128. }
129. 
     
130. void traverse()
131. {
132. struct node *t;
133. t=start;
134. while(t->next!=NULL)
135. {
136. printf("\n %d",t->data);
137. t=t->next;
138. }
139. printf("\n %d\n\n",t->data);
140. while(t->prev!=NULL)
141. {
142. printf("\n %d",t->data);
143. t=t->prev;
144. }
145. printf("\n %d\n\n",t->data);
146. }