title
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.
solution
class MyHashMap {
public:
/** Initialize your data structure here. */
int data[1000001];
MyHashMap() {
fill(data,data+1000001,-1);
}
/** value will always be non-negative. */
void put(int key, int value) {
data[key]=value;
}
/** Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key */
int get(int key) {
return data[key];
}
/** Removes the mapping of the specified value key if this map contains a mapping for the key */
void remove(int key) {
data[key]=-1;
}
};
/**
* Your MyHashMap object will be instantiated and called as such:
* MyHashMap obj = new MyHashMap();
* obj.put(key,value);
* int param_2 = obj.get(key);
* obj.remove(key);
*/