DesignHashSet

Author: FeiCoding

(#705)DesignHashSet/DesignHashSet.java

@@ -0,0 +1,58 @@
+class MyHashSet {
+    private final int SIZE = 100000;
+    private List<Integer> bucket[];
+    /** Initialize your data structure here. */
+    public MyHashSet() {
+        bucket = new List[SIZE];
+    }
+    
+    private int hash(int key){
+        return key % SIZE;
+    }
+    
+    private int getPos(int key, int index){
+        List<Integer> list = bucket[index];
+        if(list == null) return -1;
+        for(int i = 0; i < list.size(); i++){
+            if(list.get(i) == key)
+                return i;
+        }
+        return -1;
+    }
+    
+    public void add(int key) {
+        int y = hash(key);
+        int pos = getPos(key, y);
+        if(pos < 0) {
+            if(bucket[y] == null)
+                bucket[y] = new ArrayList<Integer>();
+            bucket[y].add(key);
+        }
+        
+    }
+    
+    public void remove(int key) {
+        int y = hash(key);
+        int pos = getPos(key, y);
+        if(pos < 0) return;
+        else{
+            bucket[y].remove(pos);
+        }
+    }
+    
+    /** Returns true if this set contains the specified element */
+    public boolean contains(int key) {
+        int y = hash(key);
+        int pos = getPos(key, y);
+        if(pos < 0) return false;
+        else return true;
+    }
+}
+
+/**
+ * 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);
+ */