Adjacent matrix

Question

How can I combine these two functions to create a program that will allow a user to enter the count of vertices and then enter the graph edges?

#include <iostream>
using namespace std;

int **malloc2d(int r, int c)
{
    int **t = new int*[r];
    for(int i = 0; i < r; i++)
        t[i] = new int[c];
    return t;
}

int main()
{
    int i;
    int j;
    int adj[V][V];
    for(i = 0; i < V; i++)
        for(j = 0 ; j < V; j++)
            adj[i][j] = 0;

    for(i = 0; i < V; i++)
        adj[i][i]= 1;
    while (cin>> i >> j)
    {
        adj[i][j] = 1;
        adj[j][i] = 1;
    }

    system("pause");
    return 0;
}

Answer 1

You could use std::vector<std::vector<bool>> or boost::adjacency_matrix, it's simpler.

std::size_t v;
std::cin >> v;

std::vector<std::vector<bool>> g(v);
for(auto& elem: g)
    elem.resize(v, false);

boost::adjacency_matrix<boost::undirectedS> ug(v);

std::size_t e;
std::cin >> e;

for(std::size_t i = 0; i < e; ++i)
{
    std::size_t v1, v2;
    std::cin >> v1 >> v2;

    g.at(v1).at(v2) = true;
    g.at(v2).at(v1) = true;

    boost::add_edge(v1, v2, ug);
}