Design HashMap.cpp

class MyHashMap {
public:
    unordered_map<int,int> um;
    /** Initialize your data structure here. */
    MyHashMap() {
     um;
    }
    
    /** value will always be non-negative. */
    void put(int key, int value) {
        um[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) {
        if(um.find(key)==um.end()) return -1; 
        return  um[key];
    }
    
    /** Removes the mapping of the specified value key if this map contains a mapping for the key */
    void remove(int key) {
        um.erase(key);
    }
};

/**
 * 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);
 */