edge_list.cpp

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

#define _CRT_SECURE_NO_DEPRECATE
#define __elshorpagi__ (ios_base::sync_with_stdio(false), cin.tie(NULL))
#define all(v) ((v).begin()), ((v).end())
#define sz(v) ((int)((v).size()))
#define edl '\n'

/*----Problem #1: Edge List Representation--------------------*/

struct Edge
{
    int from, to, weight;
    Edge(int from, int to, int weight) : from(from), to(to), weight(weight) {}
    bool operator<(const Edge &e) const
    {
        return weight < e.weight;
    }
    void print()
    {
        cout << "Edge (" << from << " " << to << " " << weight << ")" << edl;
    }
};

typedef vector<Edge> GRAPH;

void add_edge_list_reper(GRAPH &graph, int from, int to, int weight)
{
    graph.push_back({from, to, weight});
}

void print_adjaceny_edge_list(GRAPH &graph)
{
    int len(sz(graph));
    for (int e(0); e < len; ++e)
        graph[e].print();
}

void Solve()
{
    // this representation in general is slower representation
    // and it's has very limited usege, but it's very simple
    int nodes, edges;
    cin >> nodes >> edges;

    GRAPH graph;

    for (int e(0); e < edges; ++e)
    {
        int from, to, weight;
        cin >> from >> to >> weight;
        add_edge_list_reper(graph, from, to, weight);
    }
    sort(all(graph)); // sort depend on the operator overloading;
    print_adjaceny_edge_list(graph);
    cout << edl << "DONE" << edl;
}

int main()
{
    __elshorpagi__;
    freopen("../test/input.txt", "r", stdin);
    freopen("../test/output.txt", "w", stdout);
    int tc(1);
    // cin >> tc;
    while (tc--)
        Solve();
    return (0);
}