add 3217

Author: fishercoder1534

Diff for: paginated_contents/algorithms/4th_thousand/README.md

@@ -1,5 +1,6 @@
 | #    | Title                                                                                                                                                               | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
+| 3217 | [Delete Nodes From Linked List Present in Array](https://leetcode.com/problems/delete-nodes-from-linked-list-present-in-array/)                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3217.java) |                                                                               | Medium     | LinkedList 
 | 3216 | [Lexicographically Smallest String After a Swap](https://leetcode.com/problems/lexicographically-smallest-string-after-a-swap/)                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3216.java) |                                                                               | Easy       | Greedy
 | 3212 | [Count Submatrices With Equal Frequency of X and Y](https://leetcode.com/problems/count-submatrices-with-equal-frequency-of-x-and-y/)                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3212.java) |                                                                               | Medium     | Prefix Sum
 | 3211 | [Generate Binary Strings Without Adjacent Zeros](https://leetcode.com/problems/generate-binary-strings-without-adjacent-zeros/)                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3211.java) |                                                                               | Medium     | Recursion, Backtracking

Diff for: src/main/java/com/fishercoder/solutions/fourththousand/_3217.java

@@ -0,0 +1,38 @@
+package com.fishercoder.solutions.fourththousand;
+
+import com.fishercoder.common.classes.ListNode;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class _3217 {
+    public static class Solution1 {
+        public ListNode modifiedList(int[] nums, ListNode head) {
+            Set<Integer> set = new HashSet<>();
+            for (int num : nums) {
+                set.add(num);
+            }
+            ListNode tmp = head;
+            List<Integer> list = new ArrayList<>();
+            while (tmp != null) {
+                if (!set.contains(tmp.val)) {
+                    list.add(tmp.val);
+                }
+                tmp = tmp.next;
+            }
+            if (list.size() == 0) {
+                return null;
+            }
+            ListNode pre = new ListNode(-1);
+            ListNode tmp2 = new ListNode(list.get(0));
+            pre.next = tmp2;
+            for (int i = 1; i < list.size(); i++) {
+                tmp2.next = new ListNode(list.get(i));
+                tmp2 = tmp2.next;
+            }
+            return pre.next;
+        }
+    }
+}