ADD: Linked list code

Author: InclinedScorpio

data-structures/linked-list/insertion/creating_linked_list.cpp

@@ -0,0 +1,33 @@
+#include <iostream>
+
+using namespace std;
+
+class Node {
+    public:
+        int data;
+        Node* next;
+        Node(int data) {
+            this->data = data;
+            this->next = NULL;
+        }
+};
+
+/**
+ * Both recursive and iterative approach can be used
+ * 
+ */ 
+Node* insertAtHead(Node* head, int data) {
+	if(head==NULL) {
+		return new Node(data);
+	}
+	head->next = insertAtHead(head->next, data);
+	return head;
+}
+
+int main() {
+	int arr[] = {1, 2, 3, 4, 5};
+	Node* head = NULL;
+	for(int i: arr) {
+		head = insertAtHead(head, i);
+	}
+}

data-structures/linked-list/traversing/print_linked_list.cpp

@@ -0,0 +1,37 @@
+#include <iostream>
+
+using namespace std;
+
+class Node {
+    public:
+        int data;
+        Node* next;
+        Node(int data) {
+            this->data = data;
+            this->next = NULL;
+        }
+};
+
+Node* insertAtHead(Node* head, int data) {
+	if(head==NULL) {
+		return new Node(data);
+	}
+	head->next = insertAtHead(head->next, data);
+	return head;
+}
+
+void printLinkedList(Node* head) {
+	while(head!=NULL) {
+		cout<<head->data<<" ";
+		head = head->next;
+	}
+}
+
+int main() {
+	int arr[] = {1, 2, 3, 4, 5};
+	Node* head = NULL;
+	for(int i: arr) {
+		head = insertAtHead(head, i);
+	}
+	printLinkedList(head);
+}

data-structures/binary-tree/.DS_Store renamed to data-structures/tree/binary-tree/.DS_Store

@@ -16,19 +16,25 @@ class Node {
 };
 
 int closest = INT_MAX;
+int nearestValue;
 /**
- * COMPLEXITY: O(Height) - in case of recursion we will traverse till the last
- * O(1) - in case of iterative approach
+ * TIME-COMPLEXITY: O(N)
+ * SPACE-COMPLEXITY: O(Height) - recursion | O(1) - iterative
  * LOGIC: Pick the required branch on each step
  * 
  */ 
 int closestInBST(Node* node, int key){
     if(node==NULL) {
-        return closest;
+        return nearestValue;
     }
     int currClosest = abs(node->data - key);
+    if(currClosest == 0) {
+        return node->data;
+    }
+
     if(closest > currClosest) {
-        closest = node->data;
+        nearestValue = node->data;
+        closest = currClosest;
     }
     if (node->data > key) {
         return closestInBST(node->left, key);
@@ -45,8 +51,8 @@ int main() {
     root->left->right = new Node(6);
     root->left->right->left = new Node(4);
     root->left->right->right = new Node(7);
-    root->right->right = new Node(12);
-    root->right->right->right = new Node(23);
+    root->right->right = new Node(15);
+    root->right->right->right = new Node(25);
     root->right->right->left = new Node(13);
     cout<<closestInBST(root, 16);
 }