Design a HashMap without using any built-in hash table libraries.
To be specific, your design should include these functions:
put(key, value): Insert a (key, value) pair into the HashMap. If the value already exists in the HashMap, update the value.get(key): Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key.remove(key): Remove the mapping for the value key if this map contains the mapping for the key.
Example:
MyHashMap hashMap = new MyHashMap(); hashMap.put(1, 1); hashMap.put(2, 2); hashMap.get(1); // returns 1 hashMap.get(3); // returns -1 (not found) hashMap.put(2, 1); // update the existing value hashMap.get(2); // returns 1 hashMap.remove(2); // remove the mapping for 2 hashMap.get(2); // returns -1 (not found)
Note:
- All keys and values will be in the range of
[0, 1000000]. - The number of operations will be in the range of
[1, 10000]. - Please do not use the built-in HashMap library.
class MyHashMap(object):
def __init__(self):
"""
Initialize your data structure here.
"""
self._data={}
def put(self, key, value):
"""
value will always be non-negative.
:type key: int
:type value: int
:rtype: void
"""
self._data[key]=value
def get(self, key):
"""
Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key
:type key: int
:rtype: int
"""
if key in self._data:
return self._data[key]
else:
return -1
def remove(self, key):
"""
Removes the mapping of the specified value key if this map contains a mapping for the key
:type key: int
:rtype: void
"""
if key in self._data:
del self._data[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)