Function add_edge

graph/code14.cpp:14–18

const int inf = 1e9 + 7;

void add_edge(vector<pair<int, int>> vec[], int u, int v, int weight)
{
    vec[u].push_back({v, weight});
    vec[v].push_back({u, weight});
}

// this algo is without using priority queue
void prims_algo1(vector<pair<int, int>> vec[], int v)