706. Design HashMap (Easy)
https://leetcode.com/problems/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.
Solutions
class MyHashMap {
int[] map;
public MyHashMap() {
map = new int[1000001];
Arrays.fill(map, -1);
}
public void put(int key, int value) {
map[key] = value;
}
public int get(int key) {
return map[key];
}
public void remove(int key) {
map[key] = -1;
}
}