Reverse Doubly Linked List

Author: MohammadFahad1

reverse_doubly_linked_list.cpp

@@ -0,0 +1,72 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Node
+{
+public:
+    int val;
+    Node *next;
+    Node *prev;
+    Node(int val)
+    {
+        this->val = val;
+        this->next = NULL;
+        this->prev = NULL;
+    }
+};
+
+void print_reverse(Node *head)
+{
+    Node *tmp = head;
+    if (tmp == NULL)
+        return;
+    print_reverse(tmp->next);
+    cout << tmp->val << " ";
+}
+
+void print(Node *head)
+{
+    Node *tmp = head;
+    while (tmp != NULL)
+    {
+        cout << tmp->val << " ";
+        tmp = tmp->next;
+    }
+    cout << endl;
+}
+
+void reverse(Node *head, Node *tail)
+{
+    Node *i = head;
+    Node *j = tail;
+    while (i != j && i->next != j)
+    {
+        swap(i->val, j->val);
+        i = i->next;
+        j = j->prev;
+    }
+}
+
+int main()
+{
+    Node *head = new Node(10);
+    Node *a = new Node(20);
+    Node *b = new Node(30);
+    Node *c = new Node(40);
+    Node *d = new Node(50);
+    Node *tail = d;
+    head->next = a;
+    a->prev = head;
+    a->next = b;
+    b->prev = a;
+    b->next = c;
+    c->prev = b;
+    c->next = d;
+    d->prev = c;
+
+    // print_reverse(head);
+    reverse(head, tail);
+    print(head);
+
+    return 0;
+}