01_create_and_print_graph.cpp

/*
    link: https://www.javatpoint.com/graph-theory-graph-representations#:~:text=In%20graph%20theory%2C%20a%20graph,to%20it%20by%20an%20edge).

    link: https://onedrive.live.com/?authkey=%21AJrTq%5FU8BPKIWDk&cid=842AECBB531CCEA4&id=842AECBB531CCEA4%211179&parId=842AECBB531CCEA4%211164&o=OneUp

*/


// ----------------------------------------------------------------------------------------------------------------------- //
/*
    using adjacency matrix:

    TC: O(1) => for searching
    SC: O(N^2)
*/

int adjMatrix() {
    int rows, cols;
    cin >> rows >> cols;

    int adj[rows + 1][rows + 1];

    for (int i = 0;i < rows;i++) {
        int u, v;
        cin >> u >> v;
        adj[u][v] = 1;
        adj[v][u] = 1;
    }
}





// ----------------------------------------------------------------------------------------------------------------------- //
/*
    using adjacency list

    TC: O(Edges of that vertex)
    SC: O(N + (2*E))
*/

int adjList() {
    int rows, cols;
    cin >> rows >> cols;

    vector<int> adj(rows + 1);

    for (int i = 0;i < m;i++) {
        int u, v;
        cin >> u >> v;

        adj[u].push_back(v);
        adj[v].push_back(u);        // comment this line for directed graph

        // for weighted graph use: adj[u].push_back({v, wt});
        //                         adj[v].push_back({u, wt});
    }
}