Design HashMap LeetCode solution in C++

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class MyHashMap {
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  vector<vector<pair<int, int>>> map;
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  const int size = 10000;
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 public:
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  /** Initialize your data structure here. */
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  MyHashMap() {
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    map.resize(size);
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  }
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  /** value will always be non-negative. */
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  void put(int key, int value) {
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    int index = key % size;
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    vector<pair<int, int>> &row = map[index];
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    for (auto iter = row.begin(); iter != row.end(); iter++) {
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      if (iter->first == key) {
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        iter->second = value;
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        return;
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      }
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    }
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    row.push_back(make_pair(key, value));
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  }
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  /** Returns the value to which the specified key is mapped, or -1 if this map
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   * contains no mapping for the key */
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  int get(int key) {
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    int index = key % size;
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    vector<pair<int, int>> &row = map[index];
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    for (auto iter = row.begin(); iter != row.end(); iter++) {
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      if (iter->first == key) {
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        return iter->second;
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      }
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    }
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    return -1;
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  }
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  /** Removes the mapping of the specified value key if this map contains a
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   * mapping for the key */
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  void remove(int key) {
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    int index = key % size;
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    vector<pair<int, int>> &row = map[index];
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    for (auto iter = row.begin(); iter != row.end(); iter++) {
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      if (iter->first == key) {
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        row.erase(iter);
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        return;
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      }
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    }
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  }
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};
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/**
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 * Your MyHashMap object will be instantiated and called as such:
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 * MyHashMap* obj = new MyHashMap();
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 * obj->put(key,value);
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 * int param_2 = obj->get(key);
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 * obj->remove(key);
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 */