Updated SLL code

LinkedList/SLL.cpp

@@ -1,61 +1,289 @@
-// A simple C program for traversal of a linked list
-#include<stdio.h>
-#include<stdlib.h>
-#include <iostream>
-struct Node 
+#include <stdio.h>
+#include <stdlib.h>
+
+int count=0;
+
+struct node
 {
   int data;
-  struct Node *next;
+  struct node *next;
 };
-
-// This function prints contents of linked list starting from 
-// the given node
-void printList(struct Node *n)
+
+struct node *head = NULL;
+
+void insert_at_beginning(int num)
+{
+  struct node *t;
+  t = (struct node*) malloc (sizeof(struct node));
+  if(head == NULL)
+  {
+    head=t;
+    head->data=num;
+    head->next=NULL;
+    count=1;
+  }
+  else
+  {
+    t->data=num;
+    t->next=head;
+    head=t;
+    count++;
+  }
+}
+
+void insert_at_end(int num)
 {
-  while (n != NULL)
+  struct node *t,*temp;
+  t = (struct node*) malloc (sizeof(struct node));
+  if(head == NULL)
+  {
+    head=t;
+    head->data=num;
+    head->next=NULL;
+    count=1;
+  }
+  else
   {
-     printf("%d ", n->data);
-     n = n->next;
+    temp=head;
+    while(temp->next!=NULL)
+    {
+      temp=temp->next;
+    }
+    temp->next=t;
+    t->data=num;
+    t->next=NULL;
+    count++;
   }
-  std::cout << "\n";
-
 }
 
-size_t length(struct Node* n)
+void insert_in_middle(int num, int pos)
 {
-    size_t length = 0;
-    struct Node * iterator = NULL;
-    iterator = n;
+  int i=1;
+  struct node *t,*node;
+  if(pos>count || pos<1)
+  {
+    printf("Element can't be inserted at such position\n\n");
+  }
+  else
+  {
+    t = (struct node*) malloc (sizeof(struct node));
+    node=head;
+    while(i==pos)
+    {
+      node=node->next;
+      i++;
+    }
+    node=node->next;
+    t->data=num;
+    t->next=node->next;
+    node->next=t;
+  }
+}
 
-    while(iterator)
+void traverse()
+{
+  struct node *t;
+  t=head;
+  if(t==NULL)
+  {
+    printf("Linked List is Empty");
+  }
+  else
+  {
+    printf("Elements in Linked List are : ");
+    while(t->next!=NULL)
     {
-        ++length;
-        iterator = iterator->next;
+      printf("%d -> ",t->data);
+      t=t->next;
     }
-    return length;
+    printf("%d",t->data);
+  }
 }
+
+void delete_from_beginning()
+{
+  struct node *t;
+  if(head==NULL)
+  {
+    printf("Nothing to delete.\nLinked List is empty.");
+  }
+  else
+  {
+    printf("Deleted element is %d\n",head->data);
+    t=head->next;
+    free(head);
+    head=t;
+    count--;
+  }
+}
+
+void delete_from_end()
+{
+  struct node *t,*end_node;
+  if(head==NULL)
+  {
+    printf("Nothing to delete.\nLinked List is empty.");
+  }
+  else if(head->next==NULL)
+  {
+    printf("Deleted element is %d\n",head->data);
+    free(head);
+    head=NULL;
+    count=0;
+  }
+  else
+  {
+    t=head;
+    while(t->next!=NULL)
+    {
+      end_node=t;
+      t=t->next;
+    }
+      printf("Deleted element is %d\n",t->data);
+      end_node->next=NULL;
+      free(t);
+      count--;
+  }
+}
+
+void delete_from_middle(int pos)
+{
+  int i=1;
+  struct node *temp,*node;
+  if(pos>count || pos<1)
+  {
+    printf("Element do not exist at such position\n\n");
+  }
+  else
+  {
+    node=head;
+    while(i==pos)
+    {
+      node=node->next;
+      i++;
+    }
+    node=node->next;
+    temp=node->next;
+    node->next=temp->next;
+    free(temp);
+  }
+}
+
+void wait()
+{
+  printf("\n\n");
+  printf("Press ENTER to continue...");
+  getchar();
+  getchar();
+}
+
 int main()
 {
-  struct Node* head = NULL;
-  struct Node* second = NULL;
-  struct Node* third = NULL;
-
-  // allocate 3 nodes in the heap  
-  head  = (struct Node*)malloc(sizeof(struct Node)); 
-  second = (struct Node*)malloc(sizeof(struct Node));
-  third  = (struct Node*)malloc(sizeof(struct Node));
-
-  head->data = 1; //assign data in first node
-  head->next = second; // Link first node with second   
-
-  second->data = 2; //assign data to second node
-  second->next = third;  
-
-  third->data = 3; //assign data to third node
-  third->next = NULL;
-
-  printList(head);
-  std::cout << length(head) << "\n";
-
+  int choice;
+  int element;
+  int position;
+  while(1)
+  {
+    system("clear");
+    printf("                            LINKED LIST DATA STRUCTURE");
+    printf("\n");
+    printf("--------------------------------------------------------------------------------");
+    printf("\n\n");
+    printf("List of Operations :  1. Insert at Beginning\n");
+    printf("                      2. Insert at End\n");
+    printf("                      3. Insert in Middle\n");
+    printf("                      4. Delete from Beginning\n");
+    printf("                      5. Delete from End\n");
+    printf("                      6. Delete from Middle\n");
+    printf("                      7. Traverse\n");
+    printf("                      8. Number of Elements\n");
+    printf("                      0. Exit\n");
+    printf("\n\n\n");
+    printf("Enter the Number of Operation you want to perform : ");
+    scanf("%d",&choice);
+    printf("\n\n");
+
+    switch(choice)
+    {
+      case 1:
+        printf("Enter the number you want to insert : ");
+        scanf("%d",&element);
+        insert_at_beginning(element);
+        traverse();
+        wait();
+        break;
+      case 2:
+        printf("Enter the number you want to insert : ");
+        scanf("%d",&element);
+        insert_at_end(element);
+        traverse();
+        wait();
+        break;
+      case 3:
+        printf("Enter the number you want to insert : ");
+        scanf("%d",&element);
+        printf("Enter the position of number : ");
+        scanf("%d",&position);
+        if(position==1)
+        {
+          insert_at_beginning(element);
+        }
+        else if(position==count+1)
+        {
+          insert_at_end(element);
+        }
+        else
+        {
+          insert_in_middle(element,position);
+        }
+        traverse();
+        wait();
+        break;
+      case 4:
+        delete_from_beginning();
+        traverse();
+        wait();
+        break;
+      case 5:
+        delete_from_end();
+        traverse();
+        wait();
+        break;
+      case 6:
+        printf("Enter the position of number : ");
+        scanf("%d",&position);
+        if(position==1)
+        {
+          delete_from_beginning();
+        }
+        else if(position==count)
+        {
+          delete_from_end();
+        }
+        else
+        {
+          delete_from_middle(position);
+        }
+        traverse();
+        wait();
+        break;
+      case 7:
+        traverse();
+        wait();
+        break;
+      case 8:
+        printf("Number of elements in linked list are : %d",count);
+        wait();
+        break;
+      case 0:
+        wait();
+        exit(0);
+        break;
+      default:
+        printf("Wrong input....");
+        printf("\n");
+        wait();
+    }
+  }
   return 0;
 }