Added python loops and problem solving solution

Author: omonimus1

README.md

@@ -70,7 +70,9 @@ This repository is part of the [Competitive Programmig guide](https://github.com
 | Array-DS |[C++](problem-solving/array-ds/solution.cpp)| [C++](problem-solving/array-ds/solution.py)|
 |Print Linked List|[C++](problem-solving/linked-list/print-linked-list.cpp)|[Python](problem-solving/linked-list/print-linked-list.py)|
 |Preorder Traversal Tree|[C++](c++/preorder-tree)|[Python](problem-solving/preorder-tree.py)|
-|PostOrder Traversal Tree|[C++](problem-solving/postorder.cpp)|[Python](problem-solving/postoder.py)|
+|PostOrder Traversal Tree|[C++](problem-solving/postorder.cpp)|[Python]||Insert Node at the head of Linked List| |[C++](problem-solving/linked-list/insert-node-at-the-head.cpp)|
+|Print reverse of a linked list| |[C++](problem-solving/linked-list/print_reverse.cpp)|
+|Get the value of thenode at a specific position from the tail| |[C++](problem-solving/linked-list/get_node_from_tail.cpp)|
 
 ## Python 
 

problem-solving/linked-list/get_node_from_tail.cpp

@@ -0,0 +1,20 @@
+//https://www.hackerrank.com/challenges/get-the-value-of-the-node-at-a-specific-position-from-the-tail/problem
+int getNode(SinglyLinkedListNode* head, int positionFromTail) {
+    // Check if the linked list is empty
+    if(head == NULL)
+        return -1;
+    int number_of_nodes = get_number_of_nodes(head);
+    int position = number_of_nodes-positionFromTail;
+    int counter = 0;
+    while(head != NULL)
+    {
+        counter++;
+        if(position == counter)
+        {
+            return head->data;
+        }
+        head = head->next;
+    }
+    // Something went wrong
+    return -1;
+}

problem-solving/linked-list/insert-node-at-the-head.cpp

@@ -0,0 +1,8 @@
+// https://www.hackerrank.com/challenges/insert-a-node-at-the-head-of-a-linked-list/problem
+SinglyLinkedListNode* insertNodeAtHead(SinglyLinkedListNode* llist, int data) {
+   SinglyLinkedListNode *new_node = new SinglyLinkedListNode(data);
+    new_node -> data = data;
+    new_node->next = (llist);
+    llist = new_node;
+    return llist;
+}

problem-solving/linked-list/print_reverse.cpp

@@ -0,0 +1,7 @@
+//https://www.hackerrank.com/challenges/print-the-elements-of-a-linked-list-in-reverse/problem
+void reversePrint(SinglyLinkedListNode* head) {
+    if(head == NULL)
+        return;
+    reversePrint(head->next);
+    cout << head->data<<endl;
+}