Leetcode 817 Solution

https://leetcode.com/problems/design-hashmap

Solution

``````class MyHashMap {
vector<list<pair<int, int>>> hash_map;

public:
/** Initialize your data structure here. */
MyHashMap() {
hash_map.resize(7927);
}

/** value will always be non-negative. */
void put(int key, int value) {
auto hash_key = key % 7927;

auto& hash_vals = hash_map[hash_key];

for (auto it = hash_vals.begin(); it != hash_vals.end(); it++)
{
if (it->first == key)
{
it->second = value;
return;
}
}

hash_vals.push_back(make_pair(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 hash_key = key % 7927;

auto& hash_vals = hash_map[hash_key];

for (auto it = hash_vals.begin(); it != hash_vals.end(); it++)
{
if (it->first == key)
return it->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 hash_key = key % 7927;

auto& hash_vals = hash_map[hash_key];

for (auto it = hash_vals.begin(); it != hash_vals.end(); it++)
{
if (it->first == key)
{
hash_vals.erase(it);
return;
}
}
}
};

/**
* 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);
*/
``````