Submission #564027

#	Time	Username	Problem	Language	Result	Execution time	Memory
564027		Cyanmond	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	466 ms	262144 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;
using i64 = int64_t;

constexpr int inf = 1 << 30;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REP3(i, l, r) for (int i = (l); i < (r); ++i)
#define RVP(i, n) for (int i = (n - 1); i >= 0; --i)

#define ALL(x) (x).begin(), (x).end()
template <typename T> bool chmin(T &a, const T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

constexpr int V = 1000000;

int main() {
    int N, M;
    cin >> N >> M;
    vector<pair<short, short>> A(M);
    REP(i, M) {
        cin >> A[i].first >> A[i].second;
        chmin(A[i].second, (short)N);
    }
    int S = 0, T = 0;
    {
        const auto as = A[0], at = A[1];
        sort(ALL(A), [](auto a, auto b) {
            if (a.second != b.second) {
                return a.second < b.second;
            }
            return a.first < b.first;
        });
        REP(i, M) {
            if (A[i] == as) S = i;
            if (A[i] == at) T = i;
        }
    }
    vector<vector<pair<short, bool>>> lst(N);
    REP(i, M) {
        if ((not lst[A[i].first].empty()) and lst[A[i].first].back().first == A[i].second) {
            lst[A[i].first].back().second = true;
            continue;
        } else {
            lst[A[i].first].push_back({A[i].second, true});
        }
        int f = A[i].first % A[i].second;
        while (f < N) {
            lst[f].push_back({A[i].second, false});
            f += A[i].second;
            if (f == A[i].first) f += A[i].second;
        }
    }

    vector<int> size_r(N + 1);
    REP(i, N) size_r[i + 1] = size_r[i] + (int)lst[i].size();

    static array<pair<int, int>, V> pair_lr;
    static array<int, V> par;
    vector<vector<int>> chd(N);
    vector<unordered_map<short, int>> id_m(N);
    REP(i, N) { REP(j, (int)lst[i].size()) id_m[i][lst[i][j].first] = size_r[i] + j; }
    REP(i, N) {
        for (const auto &[w, c] : lst[i]) {
            const int id = id_m[i][w];
            pair_lr[id] = {-1, -1};
            par[id] = size_r[N] + i;
            if (c) chd[i].push_back(id);
            const int l = i - w;
            if (l >= 0) {
                const int id2 = id_m[l][w];
                pair_lr[id].first = id2;
                pair_lr[id2].second = id;
            }
        }
    }

    static array<int, V> dist;
    fill(ALL(dist), inf);
    dist[size_r[N] + A[S].first] = 0;
    deque<int> deq;
    deq.push_back(size_r[N] + A[S].first);
    while (not deq.empty()) {
        const int f = deq.front();
        deq.pop_front();
        if (f >= size_r[N]) {
            for (const int t : chd[f - size_r[N]]) {
                if (chmin(dist[t], dist[f])) {
                    deq.push_front(t);
                }
            }
        } else {
            const auto &[l, r] = pair_lr[f];
            if (l != -1 and chmin(dist[l], dist[f] + 1)) {
                deq.push_back(l);
            }
            if (r != -1 and chmin(dist[r], dist[f] + 1)) {
                deq.push_back(r);
            }
            const int pa = par[f];
            if (chmin(dist[pa], dist[f])) {
                deq.push_front(pa);
            }
        }
    }
    auto ans = dist[size_r[N] + A[T].first];
    if (ans == inf) ans = -1;
    cout << ans << endl;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43