Submission #761420

#TimeUsernameProblemLanguageResultExecution timeMemory
761420MinaRagy06Sky Walking (IOI19_walk)C++17
10 / 100
4072 ms389600 KiB
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

vector<int> intersect[100'005];
vector<array<int, 3>> adj[100'005];
vector<ll> dist[100'005];
vector<int> idx[100'005];
int sparse[17][200'005];
const ll INF = 1e18;
ll min_distance(vector<int> x, vector<int> h, vector<int> l, vector<int> r, vector<int> y, int s, int g) {
    int n = x.size(), m = l.size();
    for (int i = 0; i < n; i++) {
        sparse[0][i] = h[i];
    }
    for (int j = 1; j < 17; j++) {
        for (int i = 0; i < n; i++) {
            sparse[j][i] = max(sparse[j - 1][i], sparse[j - 1][i + (1 << (j - 1))]);
        }
    }
    y.push_back(0);
    idx[s].push_back(m);
    dist[s].push_back(INF);
    for (int i = 0; i < m; i++) {
        int j = l[i];
        while (j <= r[i]) {
            if (y[i] <= h[j]) {
                intersect[i].push_back(j);
                j++;
                continue;
            }
            int mx = 0;
            for (int k = 16; k >= 0; k--) {
                if (y[i] > max(mx, sparse[k][j])) {
                    mx = max(mx, sparse[k][j]);
                    j += (1 << k);
                }
            }
            if (j <= r[i]) {
                intersect[i].push_back(j);
                j++;
            }
        }
        for (int k = 0; k < intersect[i].size(); k++) {
            dist[intersect[i][k]].push_back(INF);
            idx[intersect[i][k]].push_back(i);
        }
        for (int k = 0; k < intersect[i].size(); k++) {
            if (k + 1 < intersect[i].size()) {
                adj[intersect[i][k]].push_back((array<int, 3>) {intersect[i][k + 1], idx[intersect[i][k + 1]].size() - 1, y[i]});
            }
            if (k - 1 >= 0) {
                adj[intersect[i][k]].push_back((array<int, 3>) {intersect[i][k - 1], idx[intersect[i][k - 1]].size() - 1, y[i]});
            }
        }
        // assert(intersect[i].size() <= 10);
    }
    priority_queue<pair<ll, array<int, 3>>> pq;
    pq.push({0, {s, 0, 0}});
    int cnt = 0;
    while (pq.size()) {
        ll d = -pq.top().first;
        int i = pq.top().second[0];
        int j = pq.top().second[1];
        int cury = pq.top().second[2];
        pq.pop();
        if (d > dist[i][j]) continue;
        cnt++;
        assert(cnt <= 1'000'000);
        for (auto [nxt, nxth, w] : adj[i]) {
            ll newd = d + abs(x[nxt] - x[i]) + abs(cury - w);
            if (newd < dist[nxt][nxth]) {
                dist[nxt][nxth] = newd;
                pq.push({-newd, {nxt, nxth, w}});
            }
        }
    }
    ll ans = INF;
    for (int i = 0; i < dist[g].size(); i++) {
        ans = min(ans, dist[g][i] + y[idx[g][i]]);
    }
    // for (auto i : dist[g]) {
    //     ans = min(ans, i.first + i.second);
    // }
    if (ans >= INF) return -1;
    return ans;
}
// int main() {
//     ios_base::sync_with_stdio(0), cin.tie(0);
//     int N, M;
//     cin >> N >> M;
//     vector<int> X(N), H(N);
//     for (int i = 0; i < N; i++) {
//         cin >> X[i] >> H[i];
//     }
//     vector<int> L(M), R(M), Y(M);
//     for (int i = 0; i < M; i++) {
//         cin >> L[i] >> R[i] >> Y[i];
//     }
//     int S, G;
//     cin >> S >> G;
//     cout << min_distance(X, H, L, R, Y, S, G) << '\n';
//     return 0;
// }

Compilation message (stderr)

walk.cpp: In function 'll min_distance(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, int, int)':
walk.cpp:44:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         for (int k = 0; k < intersect[i].size(); k++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~~
walk.cpp:48:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |         for (int k = 0; k < intersect[i].size(); k++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~~
walk.cpp:49:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |             if (k + 1 < intersect[i].size()) {
      |                 ~~~~~~^~~~~~~~~~~~~~~~~~~~~
walk.cpp:50:118: warning: narrowing conversion of '(idx[intersect[i].std::vector<int>::operator[](((std::vector<int>::size_type)(k + 1)))].std::vector<int>::size() - 1)' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
   50 |                 adj[intersect[i][k]].push_back((array<int, 3>) {intersect[i][k + 1], idx[intersect[i][k + 1]].size() - 1, y[i]});
      |                                                                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
walk.cpp:53:118: warning: narrowing conversion of '(idx[intersect[i].std::vector<int>::operator[](((std::vector<int>::size_type)(k - 1)))].std::vector<int>::size() - 1)' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
   53 |                 adj[intersect[i][k]].push_back((array<int, 3>) {intersect[i][k - 1], idx[intersect[i][k - 1]].size() - 1, y[i]});
      |                                                                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
walk.cpp:79:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |     for (int i = 0; i < dist[g].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...