add InsertDeleteGetRandomO1.java

745344851 · May 29, 2018 · d906814 · d906814
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diff --git a/company/amazon/InsertDeleteGetRandomO1.java b/company/amazon/InsertDeleteGetRandomO1.java
@@ -0,0 +1,79 @@
+//Design a data structure that supports all following operations in average O(1) time.
+
+//insert(val): Inserts an item val to the set if not already present.
+//remove(val): Removes an item val from the set if present.
+//getRandom: Returns a random element from current set of elements. Each element must have the same probability of being returned.
+
+//Example:
+// Init an empty set.
+//RandomizedSet randomSet = new RandomizedSet();
+
+// Inserts 1 to the set. Returns true as 1 was inserted successfully.
+//randomSet.insert(1);
+
+// Returns false as 2 does not exist in the set.
+//randomSet.remove(2);
+
+// Inserts 2 to the set, returns true. Set now contains [1,2].
+//randomSet.insert(2);
+
+// getRandom should return either 1 or 2 randomly.
+//randomSet.getRandom();
+
+// Removes 1 from the set, returns true. Set now contains [2].
+//randomSet.remove(1);
+
+// 2 was already in the set, so return false.
+//randomSet.insert(2);
+
+// Since 2 is the only number in the set, getRandom always return 2.
+//randomSet.getRandom();
+
+class RandomizedSet {
+    HashMap<Integer, Integer> map;
+    ArrayList<Integer> values;
+
+    /** Initialize your data structure here. */
+    public RandomizedSet() {
+        map = new HashMap<Integer, Integer>();
+        values = new ArrayList<Integer>();
+    }
+
+    /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
+    public boolean insert(int val) {
+        if(!map.containsKey(val)) {
+            map.put(val, val);
+            values.add(val);
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
+    /** Removes a value from the set. Returns true if the set contained the specified element. */
+    public boolean remove(int val) {
+        if(map.containsKey(val)) {
+            map.remove(val);
+            values.remove(values.indexOf(val));
+            return true;
+        }
+        return false;
+    }
+
+    /** Get a random element from the set. */
+    public int getRandom() {
+        int random = (int)(Math.random() * values.size());
+        int valueToReturn = values.get(random);
+        return map.get(valueToReturn);
+    }
+}
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * RandomizedSet obj = new RandomizedSet();
+ * boolean param_1 = obj.insert(val);
+ * boolean param_2 = obj.remove(val);
+ * int param_3 = obj.getRandom();
+ */
+
diff --git a/company/facebook/InsertDeleteGetRandomO1.java b/company/facebook/InsertDeleteGetRandomO1.java
@@ -0,0 +1,79 @@
+//Design a data structure that supports all following operations in average O(1) time.
+
+//insert(val): Inserts an item val to the set if not already present.
+//remove(val): Removes an item val from the set if present.
+//getRandom: Returns a random element from current set of elements. Each element must have the same probability of being returned.
+
+//Example:
+// Init an empty set.
+//RandomizedSet randomSet = new RandomizedSet();
+
+// Inserts 1 to the set. Returns true as 1 was inserted successfully.
+//randomSet.insert(1);
+
+// Returns false as 2 does not exist in the set.
+//randomSet.remove(2);
+
+// Inserts 2 to the set, returns true. Set now contains [1,2].
+//randomSet.insert(2);
+
+// getRandom should return either 1 or 2 randomly.
+//randomSet.getRandom();
+
+// Removes 1 from the set, returns true. Set now contains [2].
+//randomSet.remove(1);
+
+// 2 was already in the set, so return false.
+//randomSet.insert(2);
+
+// Since 2 is the only number in the set, getRandom always return 2.
+//randomSet.getRandom();
+
+class RandomizedSet {
+    HashMap<Integer, Integer> map;
+    ArrayList<Integer> values;
+
+    /** Initialize your data structure here. */
+    public RandomizedSet() {
+        map = new HashMap<Integer, Integer>();
+        values = new ArrayList<Integer>();
+    }
+
+    /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
+    public boolean insert(int val) {
+        if(!map.containsKey(val)) {
+            map.put(val, val);
+            values.add(val);
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
+    /** Removes a value from the set. Returns true if the set contained the specified element. */
+    public boolean remove(int val) {
+        if(map.containsKey(val)) {
+            map.remove(val);
+            values.remove(values.indexOf(val));
+            return true;
+        }
+        return false;
+    }
+
+    /** Get a random element from the set. */
+    public int getRandom() {
+        int random = (int)(Math.random() * values.size());
+        int valueToReturn = values.get(random);
+        return map.get(valueToReturn);
+    }
+}
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * RandomizedSet obj = new RandomizedSet();
+ * boolean param_1 = obj.insert(val);
+ * boolean param_2 = obj.remove(val);
+ * int param_3 = obj.getRandom();
+ */
+
diff --git a/company/google/InsertDeleteGetRandomO1.java b/company/google/InsertDeleteGetRandomO1.java
@@ -0,0 +1,78 @@
+//Design a data structure that supports all following operations in average O(1) time.
+
+//insert(val): Inserts an item val to the set if not already present.
+//remove(val): Removes an item val from the set if present.
+//getRandom: Returns a random element from current set of elements. Each element must have the same probability of being returned.
+
+//Example:
+// Init an empty set.
+//RandomizedSet randomSet = new RandomizedSet();
+
+// Inserts 1 to the set. Returns true as 1 was inserted successfully.
+//randomSet.insert(1);
+
+// Returns false as 2 does not exist in the set.
+//randomSet.remove(2);
+
+// Inserts 2 to the set, returns true. Set now contains [1,2].
+//randomSet.insert(2);
+
+// getRandom should return either 1 or 2 randomly.
+//randomSet.getRandom();
+
+// Removes 1 from the set, returns true. Set now contains [2].
+//randomSet.remove(1);
+
+// 2 was already in the set, so return false.
+//randomSet.insert(2);
+
+// Since 2 is the only number in the set, getRandom always return 2.
+//randomSet.getRandom();
+
+class RandomizedSet {
+    HashMap<Integer, Integer> map;
+    ArrayList<Integer> values;
+
+    /** Initialize your data structure here. */
+    public RandomizedSet() {
+        map = new HashMap<Integer, Integer>();
+        values = new ArrayList<Integer>();
+    }
+
+    /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
+    public boolean insert(int val) {
+        if(!map.containsKey(val)) {
+            map.put(val, val);
+            values.add(val);
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
+    /** Removes a value from the set. Returns true if the set contained the specified element. */
+    public boolean remove(int val) {
+        if(map.containsKey(val)) {
+            map.remove(val);
+            values.remove(values.indexOf(val));
+            return true;
+        }
+        return false;
+    }
+
+    /** Get a random element from the set. */
+    public int getRandom() {
+        int random = (int)(Math.random() * values.size());
+        int valueToReturn = values.get(random);
+        return map.get(valueToReturn);
+    }
+}
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * RandomizedSet obj = new RandomizedSet();
+ * boolean param_1 = obj.insert(val);
+ * boolean param_2 = obj.remove(val);
+ * int param_3 = obj.getRandom();
+ */
diff --git a/company/twitter/InsertDeleteGetRandomO1.java b/company/twitter/InsertDeleteGetRandomO1.java
@@ -0,0 +1,79 @@
+//Design a data structure that supports all following operations in average O(1) time.
+
+//insert(val): Inserts an item val to the set if not already present.
+//remove(val): Removes an item val from the set if present.
+//getRandom: Returns a random element from current set of elements. Each element must have the same probability of being returned.
+
+//Example:
+// Init an empty set.
+//RandomizedSet randomSet = new RandomizedSet();
+
+// Inserts 1 to the set. Returns true as 1 was inserted successfully.
+//randomSet.insert(1);
+
+// Returns false as 2 does not exist in the set.
+//randomSet.remove(2);
+
+// Inserts 2 to the set, returns true. Set now contains [1,2].
+//randomSet.insert(2);
+
+// getRandom should return either 1 or 2 randomly.
+//randomSet.getRandom();
+
+// Removes 1 from the set, returns true. Set now contains [2].
+//randomSet.remove(1);
+
+// 2 was already in the set, so return false.
+//randomSet.insert(2);
+
+// Since 2 is the only number in the set, getRandom always return 2.
+//randomSet.getRandom();
+
+class RandomizedSet {
+    HashMap<Integer, Integer> map;
+    ArrayList<Integer> values;
+
+    /** Initialize your data structure here. */
+    public RandomizedSet() {
+        map = new HashMap<Integer, Integer>();
+        values = new ArrayList<Integer>();
+    }
+
+    /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
+    public boolean insert(int val) {
+        if(!map.containsKey(val)) {
+            map.put(val, val);
+            values.add(val);
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
+    /** Removes a value from the set. Returns true if the set contained the specified element. */
+    public boolean remove(int val) {
+        if(map.containsKey(val)) {
+            map.remove(val);
+            values.remove(values.indexOf(val));
+            return true;
+        }
+        return false;
+    }
+
+    /** Get a random element from the set. */
+    public int getRandom() {
+        int random = (int)(Math.random() * values.size());
+        int valueToReturn = values.get(random);
+        return map.get(valueToReturn);
+    }
+}
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * RandomizedSet obj = new RandomizedSet();
+ * boolean param_1 = obj.insert(val);
+ * boolean param_2 = obj.remove(val);
+ * int param_3 = obj.getRandom();
+ */
+
diff --git a/company/uber/InsertDeleteGetRandomO1.java b/company/uber/InsertDeleteGetRandomO1.java
@@ -0,0 +1,79 @@
+//Design a data structure that supports all following operations in average O(1) time.
+
+//insert(val): Inserts an item val to the set if not already present.
+//remove(val): Removes an item val from the set if present.
+//getRandom: Returns a random element from current set of elements. Each element must have the same probability of being returned.
+
+//Example:
+// Init an empty set.
+//RandomizedSet randomSet = new RandomizedSet();
+
+// Inserts 1 to the set. Returns true as 1 was inserted successfully.
+//randomSet.insert(1);
+
+// Returns false as 2 does not exist in the set.
+//randomSet.remove(2);
+
+// Inserts 2 to the set, returns true. Set now contains [1,2].
+//randomSet.insert(2);
+
+// getRandom should return either 1 or 2 randomly.
+//randomSet.getRandom();
+
+// Removes 1 from the set, returns true. Set now contains [2].
+//randomSet.remove(1);
+
+// 2 was already in the set, so return false.
+//randomSet.insert(2);
+
+// Since 2 is the only number in the set, getRandom always return 2.
+//randomSet.getRandom();
+
+class RandomizedSet {
+    HashMap<Integer, Integer> map;
+    ArrayList<Integer> values;
+
+    /** Initialize your data structure here. */
+    public RandomizedSet() {
+        map = new HashMap<Integer, Integer>();
+        values = new ArrayList<Integer>();
+    }
+
+    /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */
+    public boolean insert(int val) {
+        if(!map.containsKey(val)) {
+            map.put(val, val);
+            values.add(val);
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
+    /** Removes a value from the set. Returns true if the set contained the specified element. */
+    public boolean remove(int val) {
+        if(map.containsKey(val)) {
+            map.remove(val);
+            values.remove(values.indexOf(val));
+            return true;
+        }
+        return false;
+    }
+
+    /** Get a random element from the set. */
+    public int getRandom() {
+        int random = (int)(Math.random() * values.size());
+        int valueToReturn = values.get(random);
+        return map.get(valueToReturn);
+    }
+}
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * RandomizedSet obj = new RandomizedSet();
+ * boolean param_1 = obj.insert(val);
+ * boolean param_2 = obj.remove(val);
+ * int param_3 = obj.getRandom();
+ */
+