C PROGRAM TO IMPLEMENT QUEUE OPERATIONS USING ARRAY

C PROGRAM TO IMPLEMENT QUEUE OPERATIONS USING ARRAY

original post link: http://cprogramsblog.blogspot.in/2012/11/c-program-to-implement-queue-operations.html

1. #include<stdio.h>
2. #include<conio.h>
3. #define MAX 10
4. int queue[MAX], front = -1, rear = -1;
5. void Insert_Element();
6. void Delete_Element();
7. void Display_Queue();
8. void Empty_Queue();
9.  
10. int main()
11. {
12. int option;
13. printf(">>> c program to implement queue operations <<<");
14. do
15. {
16. printf("\n\n 1.Insert an element");
17. printf("\n 2.Delete an element");
18. printf("\n 3.Display queue");
19. printf("\n 4.Empty queue");
20. printf("\n 5.Exit");
21. printf("\n Enter your choice: ");
22. scanf("%d", &option);
23. switch (option)
24. {
25. case 1: Insert_Element();
26. break;
27. case 2: Delete_Element();
28. break;
29. case 3: Display_Queue();
30. break;
31. case 4: Empty_Queue();
32. break;
33. case 5: return 0; /*program ends*/
34. }
35.  
36. } while (option != 5);
37. }
38.  
39. void Insert_Element()
40. {
41. int num;
42. if (rear < MAX - 1)
43. {
44. if (front == -1)
45. /*when queue is initially empty */
46. front = 0;
47. printf("\n Enter the number to be inserted: ");
48. scanf("%d", &num);
49. rear = rear + 1;
50. queue[rear] = num;
51. }
52. else
53. {
54. printf("\n Queue OverFlow Occured");
55. }
56. }
57.  
58. void Delete_Element()
59. {
60. int element;
61.  
62. if (front == -1 || front > rear)
63. {
64. printf("\n Queue Underflow occured.\n");
65. return;
66. }
67. else
68. {
69. element = queue[front];
70. printf("\n Element deleted from queue is : %d", element);
71. front = front + 1;
72. }
73. }
74.  
75. void Display_Queue()
76. {
77. int i;
78. if (front == -1 || front > rear)
79. printf("\n No elements to display");
80. else
81. {
82. printf("\n The queue elements are:\n ");
83. for (i = front; i <= rear; i++)
84. {
85. printf("\t %d", queue[i]);
86. }
87. }
88. }
89.  
90. void Empty_Queue()
91. {
92. /*Reset queue or Creates Empty queue*/
93. front = -1;
94. rear = -1;
95. printf("\n New Queue created successfully.");
96. }

Sample output :

>>> c program to implement queue operations <<<

 1.Insert an element
 2.Delete an element
 3.Display queue
 4.Empty queue
 5.Exit
 Enter your choice: 1

 Enter the number to be inserted: 10


 1.Insert an element
 2.Delete an element
 3.Display queue
 4.Empty queue
 5.Exit
 Enter your choice: 1

 Enter the number to be inserted: 20


 1.Insert an element
 2.Delete an element
 3.Display queue
 4.Empty queue
 5.Exit
 Enter your choice: 1

 Enter the number to be inserted: 30


 1.Insert an element
 2.Delete an element
 3.Display queue
 4.Empty queue
 5.Exit
 Enter your choice: 2

 Element deleted from queue is : 10

 1.Insert an element
 2.Delete an element
 3.Display queue
 4.Empty queue
 5.Exit
 Enter your choice: 3

 The queue elements are:
         20      30

 1.Insert an element
 2.Delete an element
 3.Display queue
 4.Empty queue
 5.Exit
 Enter your choice:

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