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.

 class Bucket:
    def __init__(self):
        self.bucket = []

    def update(self, key, val):
        found = False
        for i, kv in enumerate(self.bucket):
            if kv[0] == key:
                self.bucket[i] = (key, val)
                found = True
            if found:
                break
        if not found:
            self.bucket.append((key, val))

    def get(self, key):
        for k,v in self.bucket:
            if k == key:
                return v
        return -1


    def remove(self, key):
        for i, kv in enumerate(self.bucket):
            if kv[0] == key:
                del self.bucket[i]



class MyHashMap:

    def __init__(self):
        self.key_space = 2069
        self.hash_table = [Bucket() for i in range(self.key_space)]


    def put(self, key: int, value: int) -> None:
        hash_key = key % self.key_space
        self.hash_table[hash_key].update(key, value)

    def get(self, key: int) -> int:
        hash_key = key % self.key_space 
        return self.hash_table[hash_key].get(key)


    def remove(self, key: int) -> None:        
        hash_key = key % self.key_space 
        self.hash_table[hash_key].remove(key)


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

706. Design Hashmap

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