Design hashset

/*
 * Design a HashSet without using any built-in hash table libraries.
 * Implement MyHashSet class:
 * void add(key) Inserts the value key into the HashSet.
 * bool contains(key) Returns whether the value key exists in the HashSet or not.
 * void remove(key) Removes the value key in the HashSet. If key does not exist in the HashSet, do nothing.
 * Example 1:
 * Input
 * ["MyHashSet", "add", "add", "contains", "contains", "add", "contains", "remove", "contains"]
 * [[], [1], [2], [1], [3], [2], [2], [2], [2]]
 * Output
 * [null, null, null, true, false, null, true, null, false]
 * Explanation
 * MyHashSet myHashSet = new MyHashSet();
 * myHashSet.add(1);      // set = [1]
 * myHashSet.add(2);      // set = [1, 2]
 * myHashSet.contains(1); // return True
 * myHashSet.contains(3); // return False, (not found)
 * myHashSet.add(2);      // set = [1, 2]
 * myHashSet.contains(2); // return True
 * myHashSet.remove(2);   // set = [1]
 * myHashSet.contains(2); // return False, (already removed)
 * Constraints:
 * 0 <= key <= 106
 * At most 104 calls will be made to add, remove, and contains.

 * struct MyHashSet {

 * }


 * /** 
 *  * `&self` means the method takes an immutable reference.
 *  * If you need a mutable reference, change it to `&mut self` instead.
 *  */
 * impl MyHashSet {

 *     fn new() -> Self {

 *     }

 *     fn add(&self, key: i32) {

 *     }

 *     fn remove(&self, key: i32) {

 *     }

 *     fn contains(&self, key: i32) -> bool {

 *     }
 * }
 */
struct MyHashSet {
  data: Vec<bool>,
}

impl MyHashSet {
  fn new() -> Self {
    MyHashSet { data: vec![false; 1_000_001] }
  }

  fn add(&mut self, key: i32) {
    self.data[key as usize] = true;
  }

  fn remove(&mut self, key: i32) {
    self.data[key as usize] = false;
  }

  fn contains(&self, key: i32) -> bool {
    self.data[key as usize]
  }
}