144 lines
2.2 KiB
C
144 lines
2.2 KiB
C
// Write a program to implement stack & queue using Singly linked lists.
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#include <stdio.h>
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#include <stdlib.h>
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typedef struct node
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{
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int data;
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struct node *next;
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} node;
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node *top = NULL; // For stack
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node *front = NULL, *rear = NULL; // For queue
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// Stack operations
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void push(int x)
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{
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node *newNode = (node*)malloc(sizeof(node));
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newNode->data = x;
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newNode->next = top;
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top = newNode;
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}
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int pop()
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{
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if (top == NULL)
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{
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printf("Stack is empty\n");
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return -1;
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}
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int x = top->data;
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node *temp = top;
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top = top->next;
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free(temp);
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return x;
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}
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// Queue operations
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void enqueue(int x)
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{
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node *newNode = (node*)malloc(sizeof(node));
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newNode->data = x;
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newNode->next = NULL;
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if (rear == NULL)
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{
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front = rear = newNode;
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return;
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}
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rear->next = newNode;
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rear = newNode;
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}
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int dequeue()
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{
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if (front == NULL)
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{
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printf("Queue is empty\n");
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return -1;
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}
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int x = front->data;
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node *temp = front;
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front = front->next;
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if (front == NULL)
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rear = NULL;
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free(temp);
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return x;
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}
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// Function to display stack
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void displayStack()
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{
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node *temp = top;
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while (temp != NULL)
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{
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printf("%d ", temp->data);
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temp = temp->next;
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}
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printf("\n");
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}
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// Function to display queue
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void displayQueue()
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{
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node *temp = front;
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while (temp != NULL)
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{
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printf("%d ", temp->data);
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temp = temp->next;
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}
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printf("\n");
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}
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int main()
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{
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int choice, x;
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while (1)
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{
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printf("\n1. Push to stack\n");
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printf("2. Pop from stack\n");
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printf("3. Display stack\n");
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printf("4. Enqueue to queue\n");
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printf("5. Dequeue from queue\n");
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printf("6. Display queue\n");
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printf("7. Exit\n");
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printf("Enter your choice: ");
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scanf("%d", &choice);
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switch (choice)
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{
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case 1:
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printf("Enter element to push: ");
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scanf("%d", &x);
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push(x);
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break;
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case 2:
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x = pop();
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if (x != -1)
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printf("Popped element: %d\n", x);
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break;
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case 3:
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printf("Stack: ");
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displayStack();
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break;
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case 4:
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printf("Enter element to enqueue: ");
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scanf("%d", &x);
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enqueue(x);
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break;
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case 5:
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x = dequeue();
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if (x != -1)
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printf("Dequeued element: %d\n", x);
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break;
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case 6:
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printf("Queue: ");
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displayQueue();
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break;
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case 7:
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exit(0);
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default:
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printf("Invalid choice\n");
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}
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}
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return 0;
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}
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