Using Hash tables. Implement an unordered set. Implement an unordered set (a container for unique members) for integers in C++. It should support the following functions:void insert(val): Adds a value into the setbool has(val): Returns true if a value exists in the set, false otherwise. void rem(val): Removes a value from the set. If the value is not present, don't do anything. int size(): Returns the size of the setAll of these functions should be O(1) on average. Think about what was covered in class, specifically with hash function design and collision resolution protocols. Sample Input:get sizeinsert xget sizehas xinsert xget sizeremove xget sizehas xinsert 1-10000get sizeinsert 1-10000get sizehas 1-10000remove 1-10000get sizeSample Output:01true10falseCommencing stress test...10000100000CODE STRUCTURE:class unorderedSet {private:public:unorderedSet() {}void insert(int val) {}bool has(int val) {return false;}void rem(int val) {}int size() {return 0;}};