Submission #628036

#	Time	Username	Problem	Language	Result	Execution time	Memory
628036		vbee	Toll (BOI17_toll)	C++14	10 / 100	55 ms	6728 KiB

toll

#include <bits/stdc++.h>
#define fi first
#define se second
#define TASK "simproads"
#define pb push_back
#define all(r) (r).begin(), (r).end()
#define ll long long
#define MASK(i) (1 << (i))
#define BIT(x, i) ((x) >> (i) & 1)

using namespace std;

const int LOG = 19;
const int oo = 1e9 + 7;
const ll loo = (ll)1e18 + 7;
const int N = 5e4 + 7;

int n, k, m, q, pre[N], dist[N];
vector<pair<int, int>> g[N], queries;

void dijkstra(int root){
    for (int i = 1; i <= n; i++) dist[i] = oo;
    dist[root] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> kew;
    kew.push({0, root});
    while (!kew.empty()){
        auto k = kew.top();
        kew.pop();
        if (k.fi > dist[k.se]) continue;
        for (auto u : g[k.se]){
            if (u.se + k.fi < dist[u.fi]){
                dist[u.fi] = u.se + k.fi;
                kew.push({dist[u.fi], u.fi});
            }
        }
    }
}
struct DSU{
    vector<int> par, sz;
    int n;
    DSU(int _n){
        n = _n;
        par.resize(n + 7);
        sz.resize(n + 7);
        for (int i = 1; i <= n; i++) {
            par[i] = i;
            sz[i] = 1;
        }
    }

    int find_node(int u){
        if (u == par[u]) return u;
        else return par[u] = find_node(par[u]);
    }

    bool unify(int u, int v){
        u = find_node(u);
        v = find_node(v);
        if (u == v) return false;
        if (sz[u] < sz[v]) swap(u, v);
        sz[u] += sz[v];
        par[v] = u;
        return true;
    }

    bool same(int u, int v) {
        if (find_node(u) == find_node(v)) return true;
        return false;
    }
};
int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
//    freopen(TASK".inp", "r", stdin);
//    freopen(TASK".out", "w", stdout);
    cin >> k >> n >> m >> q;
    for (int i = 1; i <= m; i++){
        int u, v, c; cin >> u >> v >> c;
        u++; v++;
        g[u].pb({v, c});
    }
    bool flag = true;
    for (int i = 1; i <= q; i++){
        int u, v; cin >> u >> v;
        u++; v++;
        if (u != 1) flag = false;
        queries.pb({u, v});
    }
    if (k == 1){
        for (int i = 1; i <= n; i++) {
            pre[i] += pre[i - 1];
            if (g[i].size()) pre[i + 1] += g[i][0].se;
        }
        DSU dsu(n);
        for (int i = 1; i <= n; i++){
            if (g[i].size()) dsu.unify(i, i + 1);
        }
        for (int i = 0; i < queries.size(); i++){
            int u = queries[i].fi, v = queries[i].se;
            if (!dsu.same(u, v)) cout << -1 << "\n";
            else cout << pre[max(u, v)] - pre[min(u, v) - 1] << "\n";
        }
    }
    else if (flag){
        dijkstra(1);
        for (auto u : queries){
            if (dist[u.se] == oo) cout << -1 << "\n";
            else cout << dist[u.se] << "\n";
        }
    }
    else if (q <= 100){
        for (auto u : queries){
            dijkstra(u.fi);
            if (dist[u.se] == oo) cout << -1 << "\n";
            else cout << dist[u.se] <<"\n";
        }
    }
    return 0;
}

Compilation message (stderr)

toll.cpp: In function 'int main()':
toll.cpp:97:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |         for (int i = 0; i < queries.size(); i++){
      |                         ~~^~~~~~~~~~~~~~~~

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