ImplementQueueUsingStackCompleted_HashSetPending

HashSet.java

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+// Time Complexity :add,remove,contains->O(1);
+// Space Complexity :O(n); where n is no of elements
+// Did this code successfully run on Leetcode :yes
+// Any problem you faced while coding this :tried to make array as int array then realised we can use boolean
+
+class MyHashSet {
+    public int keyList = 1000;// taking keyList Size
+    public int keyItem = 1001;// taking nested array size as 1001 as item 1000000 will be on //index
+                              // arr[0][1000]
+    boolean[][] hashSet = new boolean[keyList][];// initializing list
+
+    public MyHashSet() {
+
+    }
+
+    public void add(int key) {
+        int x = key % keyList;// calculating index using hash function
+        int y = key / keyList;
+        if (hashSet[x] == null) {
+            hashSet[x] = new boolean[keyItem];// initializing nested array
+        }
+        hashSet[x][y] = true;// setting value to true
+
+    }
+
+    public void remove(int key) {
+        int x = key % keyList;
+        int y = key / keyList;
+        if (hashSet[x] != null) {
+            hashSet[x][y] = false;// removing element by setting it to false at calculated //index
+        }
+
+    }
+
+    public boolean contains(int key) {
+        int x = key % keyList;
+        int y = key / keyList;
+        if (hashSet[x] != null) {
+            return hashSet[x][y];// if nested array is not null return its status
+        }
+        return false;// else it will automatically be false
+
+    }
+}
+
+/**
+ * Your MyHashSet object will be instantiated and called as such:
+ * MyHashSet obj = new MyHashSet();
+ * obj.add(key);
+ * obj.remove(key);
+ * boolean param_3 = obj.contains(key);
+ */