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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
.
Follow up: Please do not use the built-in HashMap library.
[Design]
[Hash Table]
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