Data Structures c++

I need help implementing a weighted adjacency list graph with the following methods. It must be a weighted adjacency list. I haven't been able to find any good resources online to help me with this, so your help would be appreciated.

class Graph { private: ??? public: Graph(); // constructor must NOT have an input void insertVertex(int vertex); //inserts new vertex in graph void insertEdge(int from, int to, int weight); //inserts new edge in graph bool isEdge(int from, int to); //returns true if there is an edge between the vertices from and to int getWeight(int from, int to); //returns the weight of the edge between the vertices from and to vector getAdjacent(int vertex); //return an array of integers representing vertices adjacent to vertex };