Submission #1045620

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045620		vjudge1	Evacuation plan (IZhO18_plan)	C++17	100 / 100	296 ms	55036 KiB

plan

#include <bits/stdc++.h>
#define ll long long
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7
using namespace std;
const ll mod = 1e9 + 7;
const ll base = 837725789;
int n, m, q, k;
int spe[maxn], P[maxn];
vector<pair<int, int>> edges[maxn];
ll dist[maxn], ans[maxn];
void DJK() {
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>> > q;
    memset(dist,60, sizeof dist);
    fi(i, 1, k) q.push({0, spe[i]}), dist[spe[i]] = 0;
    while(!q.empty()) {
        int u = q.top().second; ll g = q.top().first;
        q.pop();
        if(g > dist[u]) continue;
        for(auto [v, w] : edges[u]) if(dist[v] > dist[u] + w) {
            dist[v] = dist[u] + w;
            q.push({dist[v], v});
        }
    }
}
struct DSU {
    set<int> S[maxn];
    int lab[maxn];
    DSU() { memset(lab, -1, sizeof lab); }
    int get_rt(int u) { return lab[u] < 0 ? u : lab[u] = get_rt(lab[u]); }
    void uni(int u, int v, ll w) {
        int p = get_rt(u), q = get_rt(v); if(p == q) return;
        if(lab[p] > lab[q]) swap(p, q);

        for(int x : S[q]) {
            if(S[p].find(x) != S[p].end()) ans[x] = w, S[p].erase(x);
            else S[p].insert(x);
        }
        S[q].clear();
        lab[p] += lab[q], lab[q] = p;
    }
} Dsu;
void solve()
{
    cin >> n >> m;
    fi(i, 1, m) {
        int x, y, w; cin >> x >> y >> w;
        edges[x].push_back({y, w});
        edges[y].push_back({x, w});
    }
    cin >> k;
    fi(i, 1, k) cin >> spe[i];
    cin >> q;
    fi(i, 1, q) {
        int x, y; cin >> x >> y;
        Dsu.S[x].insert(i), Dsu.S[y].insert(i);
    }
    DJK();
    fi(i, 1, n) P[i] = i;
    sort(P + 1, P + 1 + n, [](int x, int y) {
            return dist[x] > dist[y];
        });
    fi(i, 1, n) {
        int u = P[i];
        for(auto [v, w] : edges[u]) if(dist[v] >= dist[u]) Dsu.uni(u, v, dist[u]);
    }
    fi(i, 1, q) cout << ans[i] << '\n';
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    solve();
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46