Create 1836-remove-duplicates-from-an-unsorted-linked-list.js

Author: everthis

1836-remove-duplicates-from-an-unsorted-linked-list.js

@@ -0,0 +1,44 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+const deleteDuplicatesUnsorted = function(head) {
+  const set = new Set()
+  const del = new Set()
+  let cur = head
+  
+  while(cur) {
+    if(set.has(cur.val)) {
+      del.add(cur.val)
+    } else {
+      set.add(cur.val)
+
+    }
+    cur = cur.next    
+  }
+  
+  const dummy = new ListNode()
+  dummy.next = head
+  cur = dummy
+  
+  while(cur) {
+    if(cur.next) {
+      if(del.has(cur.next.val)) {
+        cur.next = cur.next.next
+      } else {
+        cur = cur.next
+      }
+    } else {
+      cur = cur.next        
+    }
+  }
+  
+  return dummy.next
+};