From 0bf3d8e3b4f008e227e5e09544f8aca4829b4639 Mon Sep 17 00:00:00 2001
From: priyanshuanand166 <73073489+priyanshuanand166@users.noreply.github.com>
Date: Thu, 13 Oct 2022 17:51:13 +0530
Subject: [PATCH] flatteningALinkedlist.cpp

Given a linked list where every node represents a linked list and contains two pointers of its type:
Pointer to next node in the main list
Pointer to a linked list where this node is headed.
---
 Linked List/flatteningALinkedlist.cpp | 79 +++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 Linked List/flatteningALinkedlist.cpp

diff --git a/Linked List/flatteningALinkedlist.cpp b/Linked List/flatteningALinkedlist.cpp
new file mode 100644
index 0000000..e839416
--- /dev/null
+++ b/Linked List/flatteningALinkedlist.cpp	
@@ -0,0 +1,79 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+// Linked list Node
+struct Node {
+	int data;
+	struct Node* next;
+	struct Node* bottom;
+
+	Node(int x)
+	{
+		data = x;
+		next = NULL;
+		bottom = NULL;
+	}
+};
+
+// comparator function for priority queue
+struct mycomp {
+	bool operator()(Node* a, Node* b)
+	{
+		return a->data > b->data;
+	}
+};
+
+void flatten(Node* root)
+{
+	priority_queue<Node*, vector<Node*>, mycomp> p;
+	// pushing main link nodes into priority_queue.
+	while (root != NULL) {
+		p.push(root);
+		root = root->next;
+	}
+
+	// Extracting the minimum node
+	// while priority queue is not empty
+	while (!p.empty()) {
+
+		// extracting min
+		auto k = p.top();
+		p.pop();
+
+		// printing least element
+		cout << k->data << " ";
+		if (k->bottom)
+			p.push(k->bottom);
+	}
+}
+
+int main()
+{
+	Node* head = new Node(5);
+	auto temp = head;
+	auto bt = head;
+	bt->bottom = new Node(7);
+	bt->bottom->bottom = new Node(8);
+	bt->bottom->bottom->bottom = new Node(30);
+	temp->next = new Node(10);
+
+	temp = temp->next;
+	bt = temp;
+	bt->bottom = new Node(20);
+	temp->next = new Node(19);
+	temp = temp->next;
+	bt = temp;
+	bt->bottom = new Node(22);
+	bt->bottom->bottom = new Node(50);
+	temp->next = new Node(28);
+	temp = temp->next;
+	bt = temp;
+	bt->bottom = new Node(35);
+	bt->bottom->bottom = new Node(40);
+	bt->bottom->bottom->bottom = new Node(45);
+
+	// Function call
+	flatten(head);
+	cout << endl;
+	return 0;
+}