Submission #723775

#	Time	Username	Problem	Language	Result	Execution time	Memory
723775		piOOE	Escape Route (JOI21_escape_route)	C++17	0 / 100	1324 ms	231504 KiB

escape_route

#include "escape_route.h"
#include <bits/stdc++.h>

using namespace std;
using ll = long long;

constexpr int N = 91;

ll dp[N][N * N][N], moment[N][N];
int siz[N];

vector<ll> calculate_necessary_time(int n, int m, ll S, int q, vector<int> A, vector<int> B, vector<ll> L, vector<ll> C,
                                    vector<int> U, vector<int> V, vector<ll> T) {
    constexpr ll inf = 3e18;
    vector<ll> answer(q, inf);
    vector<vector<int>> queries(n);

    for (int i = 0; i < q; ++i) {
        queries[U[i]].push_back(i);
    }

    vector<vector<pair<int, int>>> adj(n);

    for (int i = 0; i < m; ++i) {
        adj[A[i]].emplace_back(B[i], i);
        adj[B[i]].emplace_back(A[i], i);
    }

    auto dijkstra = [&](int source, ll s, bool rev = false) -> vector<ll> {
        vector<ll> dist(n, rev ? -inf : inf);
        dist[source] = s;
        vector<bool> used(n);

        for (int _ = 0; _ < n; ++_) {
            int v = -1;
            for (int i = 0; i < n; ++i) {
                if (!used[i] && (v == -1 || rev ^ (dist[i] < dist[v]))) {
                    v = i;
                }
            }

            used[v] = true;

            for (auto [to, i] : adj[v]) {
                ll d;
                if (rev) {
                    d = min(dist[v], C[i]) - L[i];
                } else {
                    d = L[i] + (dist[v] % S <= C[i] - L[i] ? dist[v] : (dist[v] / S + 1) * S);
                }
                if (rev ^ (dist[to] > d)) {
                    dist[to] = d;
                }
            }
        }

        for (int i = 0; i < n; ++i) {
            dist[i] = rev ? s - dist[i] : dist[i] - s;
        }

        return dist;
    };

    vector from(n, vector<ll>(n)), dto(n, vector<ll>(n));

    for (int i = 0; i < n; ++i) {
        from[i] = dijkstra(i, 0);
    }

    for (int i = 0; i < n; ++i) {
        dto[i] = dijkstra(i, S - 1, true);
    }

    for (int i = 0; i < n; ++i) {
        for (int j : queries[i]) {
            for (int mid = 0; mid < n; ++mid) {
                ll dist = S - 1 - dto[mid][i] < T[j] ? inf : S - T[j] + from[mid][V[j]];
                answer[j] = min(answer[j], dist);
            }
        }
    }

    vector<array<ll, 4>> events; //time, idx (if query then ~), x

    vector till(n, vector<ll>(m, -inf));

    for (int i = 0; i < m; ++i) {
        int a = A[i], b = B[i];
        ll t = C[i] - L[i];

        auto da = dijkstra(a, t, true);
        auto db = dijkstra(b, t, true);

        for (int x = 0; x < n; ++x) {
            da[x] = t >= da[x] ? t - da[x] : -inf;
            db[x] = t >= db[x] ? t - db[x] : -inf;

            till[x][i] = max(da[x], db[x]);
        }
    }

    for (int x = 0; x < n; ++x) {
        for (int j : queries[x]) {
            events.push_back({T[j], -inf, ~j, x});
        }
        for (int i = 0; i < m; ++i) {
            if (till[x][i] >= 0) {
                events.push_back({till[x][i], -(C[i] - L[i]), i, x});
            }
        }
    }

    sort(events.rbegin(), events.rend());

    for (int i = 0; i < n; ++i) {
        siz[i] = 1;
        fill_n(dp[i][0], n, inf);
        dp[i][0][i] = 0;
        moment[i][0] = inf;
    }

    auto distQuery = [&](int x, ll t) {
        int r = upper_bound(moment[x], moment[x] + siz[x], t, greater<>()) - moment[x];
        assert(r != 0 && (r == siz[x] || moment[x][r] < t) && moment[x][r - 1] >= t);
        return r - 1;
    };

    for (int ii = 0, jj = 0; ii < events.size(); ) {
        while (jj < events.size() && events[jj][0] == events[ii][0]) {
            jj += 1;
        }

        sort(events.begin() + ii, events.begin() + jj, [&](const auto &a, const auto &b) {
            int xa = a[3];
            int xb = b[3];
            int ia = a[2];
            int ib = b[2];

            if (ia < 0 || ib < 0) {
                return ia < 0 ? false : true;
            }

            ll dista = min(dp[xa][siz[xa] - 1][A[ia]], dp[xa][siz[xa] - 1][B[ia]]);
            ll distb = min(dp[xb][siz[xb] - 1][A[ib]], dp[xb][siz[xb] - 1][B[ib]]);

            return dista < distb;
        });

        for (; ii < jj; ++ii) {
            auto [ti, useless, j, x] = events[ii];
            if (j < 0) {
                j = ~j;
                ll d = dp[x][siz[x] - 1][V[j]];
                if (T[j] + d < S) {
                    answer[j] = min(answer[j], d);
                }
                continue;
            }

            memcpy(dp[x][siz[x]], dp[x][siz[x] - 1], sizeof(dp[x][siz[x]]));
            moment[x][siz[x]] = ti;

            int a = A[j], b = B[j];
            if (dp[x][siz[x] - 1][a] > dp[x][siz[x] - 1][b]) {
                swap(a, b);
            }

            ll distB = dp[x][siz[x] - 1][a] + L[j];
            //        cout << x << " " << j << endl;
            assert(ti + distB <= C[j]);

            if (distB < dp[x][siz[x] - 1][b]) {
                int r = distQuery(b, distB);
                for (int to = 0; to < n; ++to) {
                    dp[x][siz[x]][to] = min(dp[x][siz[x]][to], dp[b][r][to] + distB);
                }
            }

            siz[x] += 1;
        }
    }

    return answer;
}

Compilation message (stderr)

escape_route.cpp: In function 'std::vector<long long int> calculate_necessary_time(int, int, ll, int, std::vector<int>, std::vector<int>, std::vector<long long int>, std::vector<long long int>, std::vector<int>, std::vector<int>, std::vector<long long int>)':
escape_route.cpp:128:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 4> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  128 |     for (int ii = 0, jj = 0; ii < events.size(); ) {
      |                              ~~~^~~~~~~~~~~~~~~
escape_route.cpp:129:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 4> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  129 |         while (jj < events.size() && events[jj][0] == events[ii][0]) {
      |                ~~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 35
• Subtask 5: 0 / 30