Debugged old reversing singly linked list code and added a new code for the same too.

code/data_structures/src/Linked_List/Reversing_singly_LL.cpp

@@ -0,0 +1,82 @@
+#include "bits/stdc++.h"
+using namespace std;
+
+//creating a class Node for Linked List
+class Node
+{
+    public:
+        int data;
+        Node* next;
+
+        //constructor declaration
+        Node(int data)
+        {
+            this->data=data;
+            this->next=NULL;
+        }
+};
+
+//Taking reference by call to change the original Linked List and reverse it
+
+void reverseList(Node* &head) 
+{
+    Node* prev = NULL;
+    Node* forw = NULL;
+    Node* curr = head;
+
+    while(curr != NULL)
+    {
+        forw = curr -> next;
+        curr -> next = prev;
+        prev = curr;
+        curr = forw;
+    }
+    head=prev;
+}
+
+//insertion of a node at the tail of the Linked list
+void insertAtTail(Node* &tail, int data)
+{
+    Node *temp =new Node(data);
+    tail->next=temp;
+    tail=temp;
+
+}
+
+//printing out the linked list
+void print(Node * &head)
+{
+    Node * temp=head;
+
+    while(temp!=NULL)
+    {
+        cout<<temp->data<<" ";
+        temp =temp->next;
+    }
+    cout<<endl;
+}
+
+int main()
+{
+    Node * node1=new Node(0);
+
+    Node *head =node1;
+    Node* tail=node1;
+
+    insertAtTail(tail,1);
+    insertAtTail(tail,2);
+    insertAtTail(tail,3);
+    insertAtTail(tail,4);
+    insertAtTail(tail,5);
+    insertAtTail(tail,6);
+
+    cout<<"Before reversing: ";
+    print(head);
+
+    reverseList(head);
+
+    cout<<"After reversing: ";
+    print(head);
+
+    return 0;
+}

code/data_structures/src/Linked_List/reversing_linkedlist.cpp

@@ -1,56 +1,75 @@
 #include<bits/stdc++.h>
 using namespace std;
+
 struct Node{
-  int value;
-  struct Node* next;
-  Node(int value){
-    this->value=value;
-    next=NULL;
-  }
+
+    int value;
+    struct Node* next;
+
+    Node(int value)
+    {
+      this->value=value;
+      next=NULL;
+    }
 };
 
 struct LL{
-Node* head;
- LL(){
-  head=NULL;
-  }
-  void reverse(){
-  Node* curr=head;
-  Node* prev=NULL,*next=NULL;
-  while(curr!=NULL){
-  next=curr->next;
-  curr->next=prev;
-  prev=current;
-  current=next;
-  }
-  head=prev;
-  }
-  void print(){
-  struct Node* temp=head;
-  while(temp!=NULL){
-  cout<<temp->value<<" ";
-  temp=temp->next;
-  }
-  }
-  void push(int value){
-  Node* temp=new Node(value);
-  temp->next=head;
-  head=temp;
-  }
+    Node* head;
+    LL()
+    {
+        head=NULL;
+    }
+
+    void reverse()
+    {
+        Node* curr=head;
+        Node* prev=NULL,*next=NULL;
+
+        while(curr!=NULL)
+        {
+          next=curr->next;
+          curr->next=prev;
+          prev=curr;
+          curr=next;
+        }
+
+        head=prev;
+    }
+
+    void print()
+    {
+        struct Node* temp=head;
+
+        while(temp!=NULL)
+        {
+          cout<<temp->value<<" ";
+          temp=temp->next;
+        }
+    }
+
+    void push(int value)
+    {
+        Node* temp=new Node(value);
+        temp->next=head;
+        head=temp;
+    }
 };
+
 int main(){
-LL obj;
-obj.push(5);
-obj.push(60);
-obj.push(4);
-obj.push(9);
-cout<<"Entered linked list is: "<<endl;
-obj.print();
-obj.reverse();
-cout<<"Reversed linked list is: "<<endl;
-obj.print();
-  return 0;
-}
+      LL obj;
+      obj.push(5);
+      obj.push(60);
+      obj.push(4);
+      obj.push(9);
+
+      cout<<"Entered linked list is: "<<endl;
+      obj.print();
 
+      obj.reverse();
 
-}
+      cout<<"\nReversed linked list is: "<<endl;
+      obj.print();
+      cout<<endl;
+
+  return 0;
+}