Add reverse nodes problem for linked list problem

linked_list_problems/reverse_nodes.cpp

@@ -0,0 +1,73 @@
+#include <iostream>
+using namespace std;
+
+struct Node {
+    int data;
+    Node* next;
+    Node(int val) : data(val), next(nullptr) {}
+};
+
+// Function to reverse k nodes
+Node* reverseKGroup(Node* head, int k) {
+    Node* current = head;
+    Node* prev = nullptr;
+    Node* next = nullptr;
+    int count = 0;
+
+    // Count k nodes
+    Node* temp = head;
+    for (int i = 0; i < k; i++) {
+        if (!temp) return head; // Less than k nodes, return head
+        temp = temp->next;
+    }
+
+    // Reverse k nodes
+    count = 0;
+    current = head;
+    while (current != nullptr && count < k) {
+        next = current->next;
+        current->next = prev;
+        prev = current;
+        current = next;
+        count++;
+    }
+
+    // Recursively call for the next part of the list
+    if (next != nullptr) {
+        head->next = reverseKGroup(next, k);
+    }
+
+    return prev;
+}
+
+// Function to print linked list
+void printList(Node* head) {
+    while (head) {
+        cout << head->data << " -> ";
+        head = head->next;
+    }
+    cout << "NULL" << endl;
+}
+
+// Driver code
+int main() {
+    Node* head = new Node(1);
+    head->next = new Node(2);
+    head->next->next = new Node(3);
+    head->next->next->next = new Node(4);
+    head->next->next->next->next = new Node(5);
+    head->next->next->next->next->next = new Node(6);
+    head->next->next->next->next->next->next = new Node(7);
+
+    int k = 3;
+
+    cout << "Original List: ";
+    printList(head);
+
+    head = reverseKGroup(head, k);
+
+    cout << "Modified List after reversing every " << k << " nodes: ";
+    printList(head);
+
+    return 0;
+}