kyopro-lib-cpp

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:heavy_check_mark: test/onlinejudge.u-aizu.ac.jp/Maximum_Flow.0.test.cpp

Depends on

Code

#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/library/5/GRL/6/GRL_6_A"
#include "../../graph/dinic.hpp"

#include <bits/stdc++.h>
using namespace std;

int main() {
    ll v, e;
    cin >> v >> e;
    dinic<ll_dinic> dinic(v);
    while (e--) {
        ll u, v, c;
        cin >> u >> v >> c;
        dinic.add_edge(u, v, c);
    }
    ll ans = dinic.flow(0, v - 1);
    cout << ans << endl;
}
#line 1 "test/onlinejudge.u-aizu.ac.jp/Maximum_Flow.0.test.cpp"
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/library/5/GRL/6/GRL_6_A"
#line 2 "graph/dinic.hpp"

#line 2 "template.hpp"

#include <bits/stdc++.h>
using namespace std;

#define all(a) begin(a), end(a)
#define rall(a) rbegin(a), rend(a)
#define uniq(a) (a).erase(unique(all(a)), (a).end())
#define t0 first
#define t1 second
using ll = long long;
using ull = unsigned long long;
using pll = pair<ll, ll>;
using vll = vector<ll>;
constexpr double pi = 3.14159265358979323846;
constexpr ll dy[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0};
constexpr ll dx[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0};
constexpr ll sign(ll a) { return (a > 0) - (a < 0); }
constexpr ll fdiv(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }
constexpr ll cdiv(ll a, ll b) { return -fdiv(-a, b); }
constexpr ll pw(ll n) { return 1ll << n; }
constexpr ll flg(ll n) { return 63 - __builtin_clzll(n); }
constexpr ll clg(ll n) { return n == 1 ? 0 : flg(n - 1) + 1; }
constexpr ll safemod(ll x, ll mod) { return (x % mod + mod) % mod; }
template <typename T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
template <typename T> constexpr T sq(const T &a) { return a * a; }
template <typename T, typename U> constexpr bool chmax(T &a, const U &b) { return a < b ? a = b, true : false; }
template <typename T, typename U> constexpr bool chmin(T &a, const U &b) { return a > b ? a = b, true : false; }
template <typename T, typename U> ostream &operator<<(ostream &os, const pair<T, U> &a) {
    os << "(" << a.first << ", " << a.second << ")";
    return os;
}
template <typename T, typename U, typename V> ostream &operator<<(ostream &os, const tuple<T, U, V> &a) {
    os << "(" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
    os << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
    os << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
    os << ")";
    return os;
}
template <typename T, typename U> ostream &operator<<(ostream &os, const map<T, U> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
    os << ")";
    return os;
}
#ifdef ONLINE_JUDGE
#define dump(...) (void(0))
#else
void debug() { cerr << endl; }
template <typename Head, typename... Tail> void debug(Head &&head, Tail &&... tail) {
    cerr << head;
    if (sizeof...(Tail)) cerr << ", ";
    debug(tail...);
}
#define dump(...) cerr << __LINE__ << ": " << #__VA_ARGS__ << " = ", debug(__VA_ARGS__)
#endif
struct rep {
    struct itr {
        ll v;
        itr(ll v) : v(v) {}
        void operator++() { ++v; }
        ll operator*() const { return v; }
        bool operator!=(itr i) const { return v < *i; }
    };
    ll l, r;
    rep(ll l, ll r) : l(l), r(r) {}
    rep(ll r) : rep(0, r) {}
    itr begin() const { return l; };
    itr end() const { return r; };
};
struct per {
    struct itr {
        ll v;
        itr(ll v) : v(v) {}
        void operator++() { --v; }
        ll operator*() const { return v; }
        bool operator!=(itr i) const { return v > *i; }
    };
    ll l, r;
    per(ll l, ll r) : l(l), r(r) {}
    per(ll r) : per(0, r) {}
    itr begin() const { return r - 1; };
    itr end() const { return l - 1; };
};
struct io_setup {
    static constexpr int PREC = 20;
    io_setup() {
        cout << fixed << setprecision(PREC);
        cerr << fixed << setprecision(PREC);
    };
} iOS;
#line 4 "graph/dinic.hpp"

template <typename S> struct dinic {
    using C = typename S::C;
    struct _edge {
        ll to, rev;
        C cap;
    };
    struct edge {
        ll from, to;
        C cap, flow;
        friend ostream &operator<<(ostream &os, const edge &e) {
            return os << "(from: " << e.from << ", to: " << e.to << ", cap: " << e.cap << ", flow: " << e.flow << ")";
        }
    };
    vector<vector<_edge>> g;
    vector<ll> level, iter;
    vector<pair<ll, ll>> pos;
    dinic(ll n) : g(n), level(n), iter(n) {}
    ll add_edge(ll from, ll to, C cap) {
        ll from_id = g[from].size();
        ll to_id = g[to].size();
        if (from == to) ++to_id;
        g[from].push_back({to, to_id, cap});
        g[to].push_back({from, from_id, S::zero()});
        pos.emplace_back(from, from_id);
        return pos.size() - 1;
    }
    void change_edge(ll i, C new_cap, C new_flow) {
        _edge &e = g[pos[i].first][pos[i].second], &re = g[e.to][e.rev];
        e.cap = new_cap - new_flow;
        re.cap = new_flow;
    }
    C flow(ll s, ll t, C lim = S::inf()) {
        auto bfs = [&](ll s) -> void {
            fill(level.begin(), level.end(), -1);
            queue<ll> q;
            level[s] = 0;
            q.push(s);
            while (!q.empty()) {
                ll v = q.front();
                q.pop();
                for (_edge &e : g[v]) {
                    if (e.cap == S::zero() || level[e.to] >= 0) continue;
                    level[e.to] = level[v] + 1;
                    q.push(e.to);
                }
            }
        };
        auto dfs = [&](auto dfs, ll v, ll t, C lim) -> C {
            if (v == t) return lim;
            for (ll &i = iter[v]; i < (ll)g[v].size(); ++i) {
                _edge &e = g[v][i];
                if (level[v] >= level[e.to] || e.cap == S::zero()) continue;
                C d = dfs(dfs, e.to, t, lim > e.cap ? e.cap : lim);
                if (d == S::zero()) continue;
                e.cap -= d;
                g[e.to][e.rev].cap += d;
                return d;
            }
            return S::zero();
        };
        C ret = S::zero();
        while (true) {
            bfs(s);
            if (level[t] < 0 || lim == S::zero()) return ret;
            fill(iter.begin(), iter.end(), 0);
            C f;
            while ((f = dfs(dfs, s, t, lim)) != S::zero()) {
                ret += f;
                lim -= f;
            }
        }
    }
    edge get_edge(ll i) const {
        _edge e = g[pos[i].first][pos[i].second], re = g[e.to][e.rev];
        return {pos[i].first, e.to, e.cap + re.cap, re.cap};
    }
    vector<edge> edges() const {
        vector<edge> ret(pos.size());
        for (ll i : rep(pos.size())) ret[i] = get_edge(i);
        return ret;
    }
    vector<bool> cut(ll s) const {
        vector<bool> ret(g.size());
        auto dfs = [&](auto dfs, ll v) -> void {
            if (ret[v]) return;
            ret[v] = true;
            for (_edge e : g[v]) {
                if (e.cap) dfs(dfs, e.to);
            }
        };
        dfs(dfs, s);
        return ret;
    }
};

struct ll_dinic {
    using C = ll;
    static C zero() { return 0; }
    static C inf() { return numeric_limits<C>::max(); }
};
#line 3 "test/onlinejudge.u-aizu.ac.jp/Maximum_Flow.0.test.cpp"

#line 5 "test/onlinejudge.u-aizu.ac.jp/Maximum_Flow.0.test.cpp"
using namespace std;

int main() {
    ll v, e;
    cin >> v >> e;
    dinic<ll_dinic> dinic(v);
    while (e--) {
        ll u, v, c;
        cin >> u >> v >> c;
        dinic.add_edge(u, v, c);
    }
    ll ans = dinic.flow(0, v - 1);
    cout << ans << endl;
}
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