제출 #415698

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
415698		ruadhan	Robot (JOI21_ho_t4)	C++17	100 / 100	1200 ms	84332 KiB

Main

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

// const ll INF = 1e18;

// struct Edge
// {
//     int to, c;
//     ll p;
// };

// map<int, vector<Edge>> graph[100001];
// ll dp[100001];
// map<int, ll> dp2[100001], psum[100001];

// int main()
// {
//     int N, M;
//     cin >> N >> M;
//     for (int i = 0; i < M; i++)
//     {
//         int u, v, c;
//         ll p;
//         cin >> u >> v >> c >> p;
//         graph[u][c].push_back({v, c, p});
//         graph[v][c].push_back({u, c, p});
//         psum[u][c] += p;
//         psum[v][c] += p;
//     }

//     memset(dp, 0x3f, sizeof dp);
//     dp[1] = 0;
//     using T = tuple<ll, int, int>;
//     priority_queue<T, vector<T>, greater<T>> pq;
//     pq.push({0, 1, 0});

//     while (!pq.empty())
//     {
//         ll cost;
//         int node, c;
//         tie(cost, node, c) = pq.top();
//         pq.pop();

//     }

//     return 0;
// }
#include <bits/stdc++.h>

typedef long long ll;

using namespace std;

const ll INF = 1e18;

struct Edge
{

    int to, c;

    ll p;
};

map<int, vector<Edge>> graph[100001];

ll dp[100001];

map<int, ll> dp2[100001], psum[100001];

int main()
{

    cin.tie(0)->sync_with_stdio(0);

    int n, m;

    cin >> n >> m;

    for (int i = 1; i <= m; i++)
    {

        int u, v, c;

        ll p;

        cin >> u >> v >> c >> p;

        graph[u][c].push_back({v, c, p});

        graph[v][c].push_back({u, c, p});

        psum[u][c] += p;

        psum[v][c] += p;
    }

    memset(dp, 0x3f, sizeof dp);

    dp[1] = 0;

    priority_queue<tuple<ll, int, int>> pq;

    pq.push({0, 1, 0});

    while (pq.size())
    {

        ll cost;

        int node, c;

        tie(cost, node, c) = pq.top();

        pq.pop();

        if (c)
        {

            if (dp2[node][c] != -cost)
                continue;

            for (Edge i : graph[node][c])
            {

                // We can't flip i in this case

                ll case1 = psum[node][c] - i.p;

                if (case1 - cost < dp[i.to])
                {

                    dp[i.to] = case1 - cost;

                    pq.push({-dp[i.to], i.to, 0});
                }
            }
        }
        else
        {

            if (dp[node] != -cost)
                continue;

            for (auto &i : graph[node])
            {

                for (Edge j : i.second)
                {

                    // Case 1: We don't flip j

                    ll case1 = psum[node][j.c] - j.p - cost;

                    if (case1 < dp[j.to])
                    {

                        dp[j.to] = case1;

                        pq.push({-dp[j.to], j.to, 0});
                    }

                    // Case 2: We flip j but not another edge of the same colour

                    ll case2 = j.p - cost;

                    if (case2 < dp[j.to])
                    {

                        dp[j.to] = case2;

                        pq.push({-dp[j.to], j.to, 0});
                    }

                    // Case 3: We flip j and another edge of the same colour

                    ll case3 = -cost;

                    if (!dp2[j.to].count(j.c) || case3 < dp2[j.to][j.c])
                    {

                        dp2[j.to][j.c] = case3;

                        pq.push({-dp2[j.to][j.c], j.to, j.c});
                    }
                }
            }
        }
    }

    cout << (dp[n] > INF ? -1 : dp[n]);

    return 0;
}

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42