Submission #917802

#	Time	Username	Problem	Language	Result	Execution time	Memory
917802		VMaksimoski008	Toll (BOI17_toll)	C++14	18 / 100	351 ms	6396 KiB

toll

#include <bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define rall(x) x.rbegin(), x.rend()
#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

void setIO() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

int k, m, n, o;
vector<vector<pii> > graph;

int32_t main() {
    setIO();

    cin >> k >> n >> m >> o;
    graph.resize(n);

    for(int i=0; i<m; i++) {
        int a, b, w;
        cin >> a >> b >> w;
        graph[a].push_back({ b, w });
    }

    vector<pii> qus;
    int cnt0 = 0;

    for(int i=0; i<o; i++) {
        int a, b;
        cin >> a >> b;
        qus.push_back({ a, b });
        cnt0 += (a == 0);
    }

    vector<ll> dist(n, 1e18);
    vector<bool> vis(n, 0);
    priority_queue<pll, vector<pll>, greater<pll> > pq;

    auto dijkstra = [&](int start) {
        for(int i=0; i<n; i++) dist[i] = 1e18, vis[i] = 0;
        dist[start] = 0;
        pq.push({ 0, start });

        while(!pq.empty()) {
            int u = pq.top().second;
            pq.pop();

            if(vis[u]) continue;
            vis[u] = 1;

            for(auto &[v, w] : graph[u]) {
                if(dist[v] > dist[u] + w) {
                    dist[v] = dist[u] + w;
                    pq.push({ dist[v], v });
                }
            }
        }
    };

    if(cnt0 == o) {
        dijkstra(0);
        for(auto &x : qus)
            cout << (vis[x.second] ? dist[x.second] : -1) << '\n';
        return 0;
    }

    if(o <= 1000) {
        for(pii &x : qus) {
            dijkstra(x.first);
            cout << (vis[x.second] ? dist[x.second] : -1) << '\n';
        }

        return 0;
    }

    if(k == 1) {
        vector<int> edges(n);
        vector<ll> dist(n);
        for(int i=0; i<n-1; i++) {
            edges[i+1] = edges[i];
            dist[i+1] = dist[i];
            if(graph[i].size() == 1) {
                edges[i+1]++;
                dist[i+1] += graph[i][0].second;
            }
        }

        for(pii &x : qus) {
            if(edges[x.second] - edges[x.first] != x.first - x.first) cout << -1 << '\n';
            else cout << dist[x.second] - dist[x.first] << '\n'; 
        }
    }

    return 0;
}

Compilation message (stderr)

toll.cpp: In lambda function:
toll.cpp:71:23: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   71 |             for(auto &[v, w] : graph[u]) {
      |                       ^

• Subtask 1: 0 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44