Watch 10 video solutions for Design HashMap, a easy level problem involving Array, Hash Table, Linked List. This walkthrough by Ashish Pratap Singh has 1,002,140 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
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 <= 106104 calls will be made to put, get, and remove.