competitive-cpp

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View the Project on GitHub fiore57/competitive-cpp

:heavy_check_mark: test/ford-fulkerson.test.cpp

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Code

#define PROBLEM                                                                \
    "https://onlinejudge.u-aizu.ac.jp/courses/library/5/GRL/6/GRL_6_A"
// clang-format off
#include "../template/template.cpp"
#include "../graph/ford-fulkerson.cpp"
// clang-format on

void Main() {
    int V = in(), E = in();
    FordFulkerson<int> g(V);
    rep(i, E) {
        int u = in(), v = in(), c = in();
        g.add_edge(u, v, c);
    }
    out(g.max_flow(0, V - 1));
}


#line 1 "test/ford-fulkerson.test.cpp"
#define PROBLEM                                                                \
    "https://onlinejudge.u-aizu.ac.jp/courses/library/5/GRL/6/GRL_6_A"
// clang-format off
#line 1 "template/template.cpp"
#include <algorithm>
#include <array>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#ifdef _DEBUG
#define DUMP(x) std::cerr << (#x) << " = " << (x) << "\n"
#else
#define DUMP(x)
#endif
#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define EREP(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define RREP(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) REP(i, 0, n)
#define erep(i, n) EREP(i, 0, n)
#define rrep(i, n) RREP(i, n, 0)
#define ALL(r) (r).begin(), (r).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "{";
    rep(i, v.size()) os << v[i] << (i == (int)v.size() - 1 ? "" : ", ");
    os << "}";
    return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    return (os << "(" << p.first << ", " << p.second << ")");
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
    bool first = true;
    os << "{";
    for (const auto &e : m) {
        if (!first)
            os << ", ";
        os << "{" << e.first << ": " << e.second << "}";
        first = false;
    }
    os << "}";
    return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &s) {
    os << "{";
    bool first = true;
    for (const auto &e : s) {
        if (!first)
            os << ", ";
        os << e;
        first = false;
    }
    os << "}";
    return os;
}
template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &s) {
    os << "{";
    bool first = true;
    for (const auto &e : s) {
        if (!first)
            os << ", ";
        os << e;
        first = false;
    }
    os << "}";
    return os;
}
template <typename T>
T dup(T x, T y) {
    return (x + y - 1) / y;
};
template <typename A, size_t N, typename T>
inline void arrayFill(A (&array)[N], const T &val) {
    std::fill((T *)array, (T *)(array + N), val);
}
template <class T>
inline bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
struct in {
    const size_t n = 0;
    in() = default;
    in(size_t n) : n(n){};
    template <typename T>
    operator T() {
        T ret;
        cin >> ret;
        return ret;
    }
    template <typename T>
    operator vector<T>() {
        assert(n != 0);
        vector<T> ret(n);
        for (T &x : ret) {
            T tmp = in();
            x = tmp;
        }
        return ret;
    }
    template <typename T, typename U>
    operator pair<T, U>() {
        pair<T, U> ret;
        ret.first = in();
        ret.second = in();
        return ret;
    }
};

namespace fiore {
namespace impl {
template <typename T>
inline void out_impl(const T &x, char end_char) {
    std::cout << x << end_char;
}
template <typename T>
inline void out_impl(const vector<T> &x, char end_char) {
    bool first = true;
    for (const auto &e : x) {
        if (!first)
            std::cout << ' ';
        std::cout << e;
        first = false;
    }
    std::cout << end_char;
}
} // namespace impl
} // namespace fiore
template <typename T>
inline void out(const T &x) {
    fiore::impl::out_impl(x, '\n');
};
template <typename T, typename U, typename... Args>
inline void out(const T &x, const U &y, const Args &... args) {
    fiore::impl::out_impl(x, ' ');
    out(y, args...);
}

using ll = int64_t;
using vint = vector<int32_t>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pint = pair<int32_t, int32_t>;
using vpint = vector<pint>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using setint = set<int32_t>;
using qint = queue<int32_t>;
using qpint = queue<pint>;

constexpr std::int32_t INF = 1001001001;
constexpr std::int64_t LINF = 1001001001001001001;

void Main();

signed main() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << std::fixed << std::setprecision(15);
    Main();
    return 0;
}
#line 1 "graph/ford-fulkerson.cpp"
template <typename flow_t>
class FordFulkerson {
    struct edge {
        edge(const int to, const flow_t cap, const int rev, const bool is_rev,
             const int idx)
            : to(to), cap(cap), rev(rev), is_rev(is_rev), idx(idx) {}
        int to;
        flow_t cap;
        int rev;
        bool is_rev;
        int idx;
    };

public:
    vector<vector<edge>> graph;

private:
    vector<int> used;
    const flow_t INF;
    int timestamp;

public:
    explicit FordFulkerson(const int n)
        : graph(n), used(n, -1), INF(numeric_limits<flow_t>::max()),
          timestamp(0) {}

    void add_edge(const int from, const int to, const flow_t cap,
                  const int idx = -1) {
        graph[from].emplace_back(to, cap, (int)graph[to].size(), false, idx);
        graph[to].emplace_back(from, 0, (int)graph[from].size() - 1, true, idx);
    }

    flow_t dfs(const int idx, const int t, const flow_t flow) {
        if (idx == t)
            return flow;
        used[idx] = timestamp;
        for (auto &&e : graph[idx]) {
            if (e.cap > 0 && used[e.to] != timestamp) {
                flow_t d = dfs(e.to, t, min(flow, e.cap));
                if (d > 0) {
                    e.cap -= d;
                    graph[e.to][e.rev].cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

    flow_t max_flow(const int s, const int t) {
        flow_t flow = 0;
        for (flow_t f; (f = dfs(s, t, INF)) > 0; timestamp++) {
            flow += f;
        }
        return flow;
    }
};
template <typename T>
ostream &operator<<(ostream &os, const FordFulkerson<T> &f) {
    os << "\n=== vvv ===\n";
    for (size_t i = 0; i < f.graph.size(); ++i) {
        for (const auto &e : f.graph[i]) {
            if (e.is_rev)
                continue;
            auto &&rev_e = f.graph[e.to][e.rev];
            os << i << "->" << e.to << " (flow: " << rev_e.cap << "/"
               << e.cap + rev_e.cap << ")" << '\n';
        }
    }
    os << "=== ^^^ ===";
    return os;
}
#line 6 "test/ford-fulkerson.test.cpp"
// clang-format on

void Main() {
    int V = in(), E = in();
    FordFulkerson<int> g(V);
    rep(i, E) {
        int u = in(), v = in(), c = in();
        g.add_edge(u, v, c);
    }
    out(g.max_flow(0, V - 1));
}

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