706. Design HashMap
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:
def __init__(self):
"""
Initialize your data structure here.
"""
self.a = []
self.b = []
def put(self, key, value):
"""
value will always be non-negative.
:type key: int
:type value: int
:rtype: void
"""
if key in self.a:
pos = self.a.index(key)
self.b[pos] = value
else:
self.a.append(key)
self.b.append(value)
return
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.a:
pos = self.a.index(key)
return self.b[pos]
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.a:
pos = self.a.index(key)
self.a.pop(pos)
self.b.pop(pos)
return
# Your MyHashMap object will be instantiated and called as such:
# obj = MyHashMap()
# obj.put(key,value)
# param_2 = obj.get(key)
# obj.remove(key)