feat: Solve insert node in linked list

  - Hackerrank

Author: brianr482

insert-node-linked-list.js

@@ -0,0 +1,51 @@
+/**
+ * Hackerrank
+ * You’re given the pointer to the head node of a linked list, an integer to
+ * add to the list and the position at which the integer must be inserted.
+ * Create a new node with the given integer, insert this node at the desired
+ * position and return the head node.
+ * 
+ * Constraints:
+ * 1. 1 <= n <= 1000
+ * 2. 1 <= SingleLinkedListNode[i].data <= 1000
+ * 3. 0 <= position <= n
+ * 
+ * This solution got 5 points
+ * Problem link: http://hr.gs/vnu
+ */
+
+/*
+ * For your reference:
+ *
+ * SinglyLinkedListNode {
+ *     int data;
+ *     SinglyLinkedListNode next;
+ * }
+ *
+ */
+
+/**
+ * @param {SinglyLinkedListNode} head The root of the linked list
+ * @param {number} data The new data to be added to the linked list
+ * @param {number} position The index position in which the new data will be placed on
+ * @return {SinglyLinkedListNode} The root of the linked list
+ */
+function insertNodeAtPosition(head, data, position) {
+  // Edge case
+  if (!head) {
+    return { data };
+  }
+  let node = head;
+  let found = false;
+  let i = 0;
+  while (node.next && !found) {
+    if (i + 1 === position && node.next) {
+      const prev = node.next;
+      node.next = { data, next: prev };
+      found = true;
+    }
+    node = node.next;
+    i++;
+  }
+  return head;
+}