DesignHashMap.cpp

class MyHashMap {
    vector<list<pair<int,int>>> data;
    int size = 10000;
public:    
    /** Initialize your data structure here. */
    MyHashMap() {
        data.resize(size);
    }
    
    /** value will always be non-negative. */
    void put(int key, int value) {
        auto & list = data[key % size];
        for(auto &val: list) {
            if(val.first == key) {
                val.second = value;
                return;
            }
        }
        list.push_back({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) {
        auto &list = data[key % size];
        if(list.empty())
            return -1;
        for(auto &val: list) {
            if(val.first == key)
                return val.second;
        }
        return -1;
    }
    
    /** Removes the mapping of the specified value key if this map contains a mapping for the key */
    void remove(int key) {
        auto &list = data[key % size];
        for(auto val: list) {
            if(val.first == key) {
                list.remove(val);
                return;
            }
        }
    }
};