Package g0701_0800.s0706_design_hashmap

Class MyHashMap

  • public class MyHashMap
extends Object
    706 - Design HashMap\. Easy Design a HashMap without using any built-in hash table libraries. Implement the `MyHashMap` class: * `MyHashMap()` initializes the object with an empty map. * `void put(int key, int value)` inserts a `(key, value)` pair into the HashMap. If the `key` already exists in the map, update the corresponding `value`. * `int get(int key)` returns the `value` to which the specified `key` is mapped, or `-1` if this map contains no mapping for the `key`. * `void remove(key)` removes the `key` and its corresponding `value` if the map contains the mapping for the `key`. **Example 1:** **Input** ["MyHashMap", "put", "put", "get", "get", "put", "get", "remove", "get"] [ [], [1, 1], [2, 2], [1], [3], [2, 1], [2], [2], [2]] **Output:** [null, null, null, 1, -1, null, 1, null, -1] **Explanation:** MyHashMap myHashMap = new MyHashMap(); myHashMap.put(1, 1); // The map is now [[1,1]] myHashMap.put(2, 2); // The map is now [[1,1], [2,2]] myHashMap.get(1); // return 1, The map is now [[1,1], [2,2]] myHashMap.get(3); // return -1 (i.e., not found), The map is now [[1,1], [2,2]] myHashMap.put(2, 1); // The map is now [[1,1], [2,1]] (i.e., update the existing value) myHashMap.get(2); // return 1, The map is now [[1,1], [2,1]] myHashMap.remove(2); // remove the mapping for 2, The map is now [[1,1]] myHashMap.get(2); // return -1 (i.e., not found), The map is now [[1,1]] **Constraints:** * 0 <= key, value <= 106 * At most 104 calls will be made to `put`, `get`, and `remove`.

    • Constructor Detail

      • MyHashMap

        public MyHashMap()

    • Method Detail

      • put

        public void put​(int key,
                int value)

      • get

        public int get​(int key)

      • remove

        public void remove​(int key)