Submission #1089592

#	Time	Username	Problem	Language	Result	Execution time	Memory
1089592		vladilius	Evacuation plan (IZhO18_plan)	C++17	100 / 100	399 ms	66612 KiB

plan

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
#define arr3 array<int, 3>
const int inf = 1e9;

struct RT{
    vector<vector<int>> g;
    vector<int> p, a;
    int n, cc;
    RT(int ns){
        n = ns;
        p.resize(2 * n + 1);
        for (int i = 1; i <= 2 * n; i++){
            p[i] = i;
        }
        a.resize(2 * n + 1);
        g.resize(2 * n + 1);
        cc = n;
    }
    int get(int v){
        if (p[v] != v){
            p[v] = get(p[v]);
        }
        return p[v];
    }
    void add(int x, int y, int w){
        x = get(x); y = get(y);
        if (x == y) return;
        cc++;
        a[cc] = w;
        p[x] = p[y] = cc;
        g[cc].pb(x);
        g[cc].pb(y);
    }
    vector<vector<int>> pw;
    vector<int> tin, tout;
    int timer, lg;
    void dfs(int v, int pr){
        pw[v][0] = pr;
        for (int i = 1; i <= lg; i++){
            pw[v][i] = pw[pw[v][i - 1]][i - 1];
        }
        tin[v] = ++timer;
        for (int i: g[v]){
            dfs(i, v);
        }
        tout[v] = timer;
    }
    void build(){
        timer = 0;
        lg = log2(n) + 1;
        pw.resize(cc + 1);
        for (int i = 1; i <= cc; i++) pw[i].resize(lg + 1);
        tin.resize(cc + 1);
        tout.resize(cc + 1);
        dfs(cc, cc);
    }
    bool check(int x, int y){
        return (tin[x] <= tin[y] && tout[x] >= tout[y]);
    }
    int lca(int x, int y){
        if (check(x, y)) return x;
        if (check(y, x)) return y;
        for (int i = lg; i >= 0; i--){
            if (!check(pw[x][i], y)){
                x = pw[x][i];
            }
        }
        return pw[x][0];
    }
    int get(int x, int y){
        return a[lca(x, y)];
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, m; cin>>n>>m;
    vector<pii> g[n + 1];
    vector<arr3> ed;
    while (m--){
        int x, y, w; cin>>x>>y>>w;
        g[x].pb({y, w});
        g[y].pb({x, w});
        ed.pb({0, x, y});
    }
    int k; cin>>k;
    vector<int> a(k + 1), d(n + 1, inf);
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    for (int i = 1; i <= k; i++){
        cin>>a[i];
        d[a[i]] = 0;
        pq.push({0, a[i]});
    }
    
    while (!pq.empty()){
        auto [W, v] = pq.top(); pq.pop();
        for (auto [i, w]: g[v]){
            int nw = d[v] + w;
            if (d[i] > nw){
                d[i] = nw;
                pq.push({d[i], i});
            }
        }
    }

    for (auto &[w, x, y]: ed) w = min(d[x], d[y]);
    sort(ed.begin(), ed.end(), greater<arr3>());
    
    RT T(n);
    for (auto [w, x, y]: ed){
        T.add(x, y, w);
    }
    T.build();
    
    int Q; cin>>Q;
    while (Q--){
        int a, b; cin>>a>>b;
        cout<<((a == b) ? d[a] : T.get(a, b))<<"\n";
    }
}

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