operations on sorted DLL

Prasanna Devadiga/operations on sorted DLL.cpp

@@ -0,0 +1,178 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+class DoublyLinkedListNode {
+    public:
+        int data;
+        DoublyLinkedListNode *next;
+        DoublyLinkedListNode *prev;
+        DoublyLinkedListNode(int node_data) {
+            this->data = node_data;
+            this->next = NULL;
+            this->prev = NULL;
+        }
+};
+DoublyLinkedListNode *head=NULL;
+/*
+
+
+		Function to Insert a node in Sorted DLL.
+
+
+*/		
+void sortedInsert() 
+{
+	int data;
+	cout<<"Enter element to be inserted in sorted DLL: ";
+	cin>>data;
+    DoublyLinkedListNode* new_node=new DoublyLinkedListNode(data);
+    if(head==NULL)
+    {
+        head=new_node;
+    }
+    else if(head->next==NULL)
+    {
+        if(head->data>data)
+        {
+            head->prev=new_node;
+            new_node->next=head;
+            head=new_node;
+        }
+        else{
+            head->next=new_node;
+            new_node->prev=head;
+        }
+    }
+    else{
+        DoublyLinkedListNode* temp=head;
+        DoublyLinkedListNode* pre_temp=head;
+        while(temp->next!=NULL && temp->data<data)
+        {
+            pre_temp=temp;
+            temp=temp->next;
+        }
+        if(temp->prev==NULL)
+        {
+            temp->prev=new_node;
+            new_node->next=temp;
+            head=new_node;
+        }
+       else if(temp->next==NULL)
+        {
+            if(temp->data<data)
+            {
+                temp->next=new_node;
+                new_node->prev=temp;
+            }
+            else
+            {
+                pre_temp->next=new_node;
+                new_node->prev=pre_temp;
+                new_node->next=temp;
+                temp->prev=new_node;
+            }
+        }
+        else
+        {
+            pre_temp->next=new_node;
+            new_node->prev=pre_temp;
+            new_node->next=temp;
+            temp->prev=new_node;
+        }
+    }
+}
+/*
+
+ 		Funtion to delete a node fron Sorted DLL.
+
+*/
+void sortedDelete() {
+	if(head==NULL)
+	{
+		cout<<"Underflow."<<endl;
+		return;
+	}
+	int del;
+	cout<<"Enter the the element to be deleted from Sorted DLL: ";
+	cin>>del;
+	DoublyLinkedListNode* temp=head;
+	DoublyLinkedListNode* pre_temp=head;
+	while(temp->data!=del)
+	{
+		pre_temp=temp;
+		temp=temp->next;
+	}
+	if(temp->prev==NULL)
+	{
+		temp->next->prev=NULL;
+		head=temp->next;
+		free(temp);
+	}
+	else if(temp->next==NULL)
+	{
+		if(temp->prev==NULL)
+		{
+			free(temp);
+		}
+		else
+		{
+			pre_temp->next=NULL;
+			free(temp);
+		}
+	}
+	else
+	{
+		pre_temp->next=temp->next;
+		temp->next->prev=pre_temp;
+		free(temp);
+	}
+}
+/*
+
+		Function to display Sorted DLL.
+
+*/
+void sorteddisplay()
+{
+	DoublyLinkedListNode* temp=head;
+    if(temp==NULL)
+    {
+        cout<<"\nEmpty list ";
+        return;
+    }
+    while(temp->next!=NULL)
+    {
+        cout<<temp->data<<" -> ";
+        temp=temp->next;
+    }
+    cout<<temp->data;
+}
+int main()
+{
+    char ch;
+    do
+    {
+        cout<<"       SORTED DOUBLY LINKED LIST\n";
+        cout<<"\n                PRESS: ";
+        cout<<"\n            1. Insertion";
+        cout<<"\n            2. Deletion";
+        cout<<"\n            3. Display\n";
+
+        int choice;
+        cin>>choice;
+        switch(choice)
+        {
+            case 1:sortedInsert();break;
+            case 2:sortedDelete();break;
+            case 3:sorteddisplay();break;
+            default: cout<<"\nInvalid choice...breaking";
+        }
+        cout<<"\nWant to continue?(y/n)";
+
+        fflush(stdin);
+        cin>>ch;
+    }while(ch=='y'||ch=='Y');
+
+    return 0;
+}