Submission #1044278

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044278		vjudge1	Evacuation plan (IZhO18_plan)	C++17	100 / 100	389 ms	59476 KiB

plan

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
const ll oo = 1e18;

ll n, m, x, y, w, k, a[100005], q, id[100005], ans[100005], parent[100005], sz[100005];
vector<pair<ll, ll>> adj[100005];
set<ll> s[100005];
ll dist[100005];
bool mark[100005];

bool cmp(ll a, ll b){
    return dist[a] > dist[b];
}

void dijkstra(){
    for(ll i = 1; i <= n; i++) dist[i] = oo;
    priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> q;
    for(ll i = 1; i <= k; i++){
         dist[a[i]] = 0; q.push({0, a[i]});
    };
    while(!q.empty()){
        ll u = q.top().se;
        q.pop();
        if(mark[u]) continue;
        mark[u] = true;
        for(auto it : adj[u]){
            ll v = it.fi;
            ll w = it.se;
            if(dist[v] > dist[u]+w){
                dist[v] = dist[u]+w;
                q.push({dist[v], v});
            }
        }
    }
}

ll find_set(ll u){
    if(u == parent[u]) return u;
    return parent[u] = find_set(parent[u]);
}

void union_set(ll u, ll v){
    u = find_set(u);
    v = find_set(v);
    if(u == v) return;
    if(sz[u] < sz[v]) swap(u, v);
    parent[v] = u;
    sz[u]+=sz[v];
    for(auto it : s[v]){
        if(s[u].find(it) != s[u].end()){
            s[u].erase(it); ans[it] = w;
        }
        else s[u].insert(it);
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> n >> m;
    while(m--){
        cin >> x >> y >> w;
        adj[x].push_back({y, w});
        adj[y].push_back({x, w});
    }
    cin >> k;
    for(ll i = 1; i <= k; i++){
        cin >> a[i];
    }
    dijkstra();
    cin >> q;
    for(ll i = 1; i <= q; i++){
        cin >> x >> y;
        s[x].insert(i);
        s[y].insert(i);
    }
    for(ll i = 1; i <= n; i++){
        id[i] = i;
        parent[i] = i;
        sz[i] = 1;
    }
    sort(id+1, id+n+1, cmp);
    memset(mark, 0, sizeof mark);
    for(ll i = 1; i <= n; i++){
        x = id[i];
        mark[x] = true;
        w = dist[x];
        for(auto it : adj[x]){
            y = it.fi;
            if(mark[y]) union_set(x, y);
        }

    }
    for(ll i = 1; i <= q; i++) cout << ans[i] << '\n';
    return 0;
}

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