algocoon.cpp

#include <iostream>
#include <limits>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/push_relabel_max_flow.hpp>
typedef boost::adjacency_list_traits<boost::vecS, boost::vecS, boost::directedS> traits;
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::no_property,
                              boost::property<boost::edge_capacity_t, long,
                                              boost::property<boost::edge_residual_capacity_t, long,
                                                              boost::property<boost::edge_reverse_t, traits::edge_descriptor>>>>
    graph;

typedef traits::vertex_descriptor vertex_desc;
typedef traits::edge_descriptor edge_desc;

class edge_adder
{
    graph &G;

public:
    explicit edge_adder(graph &G) : G(G) {}

    void add_edge(int from, int to, long capacity)
    {
        auto c_map = boost::get(boost::edge_capacity, G);
        auto r_map = boost::get(boost::edge_reverse, G);
        const auto e = boost::add_edge(from, to, G).first;
        const auto rev_e = boost::add_edge(to, from, G).first;
        c_map[e] = capacity;
        c_map[rev_e] = 0; // reverse edge has no capacity!
        r_map[e] = rev_e;
        r_map[rev_e] = e;
    }
};

using namespace std;

void solve()
{
    int n, m;
    cin >> n >> m;

    graph G(n);
    edge_adder adder(G);

    int u, v, c;
    for (int i = 0; i < m; ++i) {
        cin >> u >> v >> c;
        adder.add_edge(u, v, c);
    }

    long minCut = numeric_limits<long>::max();

    int source = 0;
    for (int target = 1; target < n; ++target) {
        long maxFlow = boost::push_relabel_max_flow(G, source, target);
        minCut = min(minCut, maxFlow);
        maxFlow = boost::push_relabel_max_flow(G, target, source);
        minCut = min(minCut, maxFlow);
    }
    cout << minCut << endl;
}

int main()
{
    ios_base::sync_with_stdio(false);
    int t;
    cin >> t;
    for (int i = 0; i < t; ++i)
    {
        solve();
    }
    return 0;
}