結果

問題 No.1301 Strange Graph Shortest Path
コンテスト
ユーザー momohara
提出日時 2020-11-27 22:50:39
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 4,402 bytes
コンパイル時間 2,540 ms
コンパイル使用メモリ 207,188 KB
最終ジャッジ日時 2025-01-16 08:11:21
ジャッジサーバーID
（参考情報） 		judge5 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 2 WA * 31
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ソースコード

diff # 

#include <bits/stdc++.h>
using namespace std;
/*
#include <atcoder/all>
using namespace atcoder;
*/
#define all(hoge) (hoge).begin(), (hoge).end()
#define en '\n'
using ll = long long;
using ull = unsigned long long;
#define rep(i, m, n) for(ll i = (ll)(m); i < (ll)(n); ++i)
#define rep2(i, m, n) for(ll i = (ll)(n)-1; i >= (ll)(m); --i)
#define REP(i, n) rep(i, 0, n)
#define REP2(i, n) rep2(i, 0, n)
template <class T>
using vec = vector<T>;
template <class T>
using vvec = vector<vec<T>>;
typedef pair<ll, ll> P;
using tp = tuple<ll, ll, ll>;

constexpr long long INF = 1LL << 60;
constexpr int INF_INT = 1 << 25;
//constexpr long long MOD = (ll)1e9 + 7;
constexpr long long MOD = 998244353LL;
using ld = long double;
static const ld pi = 3.141592653589793L;

using Array = vector<ll>;
using Matrix = vector<Array>;

/*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
*/

template <class T>
inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}
template <typename flow_t, typename cost_t>
struct PrimalDual {
    const cost_t INF;

    struct edge {
        int to;
        flow_t cap;
        cost_t cost;
        int rev;
        bool isrev;
    };
    vector<vector<edge>> graph;
    vector<cost_t> potential, min_cost;
    vector<int> prevv, preve;

    PrimalDual(int V) : graph(V), INF(numeric_limits<cost_t>::max()) {}

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

    cost_t min_cost_flow(int s, int t, flow_t f) {
        int V = (int)graph.size();
        cost_t ret = 0;
        using Pi = pair<cost_t, int>;
        priority_queue<Pi, vector<Pi>, greater<Pi>> que;
        potential.assign(V, 0);
        preve.assign(V, -1);
        prevv.assign(V, -1);

        while(f > 0) {
            min_cost.assign(V, INF);
            que.emplace(0, s);
            min_cost[s] = 0;
            while(!que.empty()) {
                Pi p = que.top();
                que.pop();
                if(min_cost[p.second] < p.first)
                    continue;
                for(int i = 0; i < graph[p.second].size(); i++) {
                    edge &e = graph[p.second][i];
                    cost_t nextCost = min_cost[p.second] + e.cost + potential[p.second] - potential[e.to];
                    if(e.cap > 0 && min_cost[e.to] > nextCost) {
                        min_cost[e.to] = nextCost;
                        prevv[e.to] = p.second, preve[e.to] = i;
                        que.emplace(min_cost[e.to], e.to);
                    }
                }
            }
            if(min_cost[t] == INF)
                return -1;
            for(int v = 0; v < V; v++)
                potential[v] += min_cost[v];
            flow_t addflow = f;
            for(int v = t; v != s; v = prevv[v]) {
                addflow = min(addflow, graph[prevv[v]][preve[v]].cap);
            }
            f -= addflow;
            ret += addflow * potential[t];
            for(int v = t; v != s; v = prevv[v]) {
                edge &e = graph[prevv[v]][preve[v]];
                e.cap -= addflow;
                graph[v][e.rev].cap += addflow;
            }
        }
        return ret;
    }

    void output() {
        for(int i = 0; i < graph.size(); i++) {
            for(auto &e : graph[i]) {
                if(e.isrev)
                    continue;
                auto &rev_e = graph[e.to][e.rev];
                cout << i << "->" << e.to << " (flow: " << rev_e.cap << "/" << rev_e.cap + e.cap << ")" << endl;
            }
        }
    }
};

void solve() {
    int n, m;
    cin >> n >> m;
    PrimalDual<int, ll> pd(n);
    REP(i, m) {
        int u, v, c, d;
        cin >> u >> v >> c >> d;
        u--;
        v--;
        pd.add_edge(u, v, 1, c);
        pd.add_edge(u, v, 1, d);
    }

    auto ans = pd.min_cost_flow(0, n - 1, 2);
    cout << ans << en;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    /*
    ll t;
    cin >> t;
    REP(i, t - 1) {
        solve();
    }*/

    solve();

    return 0;
}
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