#706

Design HashMap

pupil · 325 · lc easy +22 · 66.4% accepted · 5,413 likes · top 72%

Description

Build a HashMap from scratch without using any built-in hash table libraries.

Implement the MyHashMap class:

- MyHashMap() Creates an empty map.

- void put(int key, int value) Stores the (key, value) pair; updates the value if key already exists.

- int get(int key) Returns the value associated with key, or -1 if no mapping exists.

- void remove(key) Deletes the mapping for key if it is present.

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]

Example 2:

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]]

Code

class MyHashMap:

    def __init__(self):
        

    def put(self, key: int, value: int) -> None:
        

    def get(self, key: int) -> int:
        

    def remove(self, key: int) -> None:
        


# Your MyHashMap object will be instantiated and called as such:
# obj = MyHashMap()
# obj.put(key,value)
# param_2 = obj.get(key)
# obj.remove(key)

class MyHashMap:

    def __init__(self):
        

    def put(self, key: int, value: int) -> None:
        

    def get(self, key: int) -> int:
        

    def remove(self, key: int) -> None:
        


# Your MyHashMap object will be instantiated and called as such:
# obj = MyHashMap()
# obj.put(key,value)
# param_2 = obj.get(key)
# obj.remove(key)