Create 448. Find All Numbers Disappeared in an Array.java

Author: futurus

448. Find All Numbers Disappeared in an Array.java

@@ -0,0 +1,21 @@
+public class Solution {
+    public List<Integer> findDisappearedNumbers(int[] nums) {
+        List<Integer> out = new ArrayList<>();
+        Map<Integer, Boolean> map = new HashMap<>();
+        for (int i = 1; i <= nums.length; i++) {
+            map.put(i, false);
+        }
+        
+        for (int i : nums) {
+            map.put(i, true);
+        }
+        
+        for (Integer i : map.keySet()) {
+            if (!map.get(i)) {
+                out.add(i);
+            }
+        }
+        
+        return out;
+    }
+}