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답안 #556693

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
556693 2022-05-03T17:03:03 Z jasmin Valley (BOI19_valley) C++14
100 / 100
 315 ms 65236 KB 
#include<bits/stdc++.h>
using namespace std;
#define int long long

int l=25;
const int inf=1e18;

struct graph{
    vector<pair<int,int> > edge;
    vector<vector<pair<int,int> > >adi;
    vector<bool> shop;
    vector<int> tin;
    vector<int> tout;
    vector<int> dist;
    vector<int> down;
    int t=0;

    vector<vector<int> > up;
    vector<vector<int> > best;

    graph(int n){
        edge.resize(n-1);
        adi.resize(n);
        shop.resize(n);
        tin.resize(n);
        tout.resize(n);
        dist.resize(n);
        down.resize(n, inf);
        up.resize(n, vector<int> (l, -1));
        best.resize(n, vector<int> (l, inf));
    }

    void dfs1(int v, int p){
        tin[v]=t; t++;

        if(shop[v]){
            down[v]=0;
        }

        for(auto u: adi[v]){
            if(u.first!=p){
                dist[u.first]=dist[v]+u.second;
                dfs1(u.first, v);
                down[v]=min(down[v], down[u.first]+u.second);
            }
        }

        tout[v]=t; t++;
    }

    void dfs2(int v, int p, int d){
        up[v][0]=p;
        if(p!=-1){
            best[v][0]=min(down[v], down[p]+d);
        }
        for(int i=1; i<l; i++){
            if(up[v][i-1]==-1) break;
            up[v][i]=up[up[v][i-1]][i-1];
            best[v][i]=min(best[v][i-1], best[up[v][i-1]][i-1]+(dist[v]-dist[up[v][i-1]]));
        }

        for(auto u: adi[v]){
            if(u.first!=p){
                dfs2(u.first, v, u.second);
            }
        }
    }

    bool is_ancestor(int a, int b){
        return tin[a]<=tin[b] && tout[b]<=tout[a];
    }
};

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, s, q, e;
    cin >> n >> s >> q >> e;
    e--;
    graph g(n);
    for(int i=0; i<n-1; i++){
        int a, b, c;
        cin >> a >> b >> c;
        a--; b--;
        g.edge[i]={a, b};
        g.adi[a].push_back({b, c});
        g.adi[b].push_back({a, c});
    }
    for(int i=0; i<s; i++){
        int a;
        cin >> a;
        a--;
        g.shop[a]=true;
    }

    g.dfs1(e, -1);
    g.dfs2(e, -1, 0);

    for(int i=0; i<q; i++){
        int x, r;
        cin >> x >> r;
        x--; r--;

        if(g.is_ancestor(g.edge[x].second, g.edge[x].first)){
            swap(g.edge[x].first, g.edge[x].second);
        }

        //cout << g.edge[x].second << " " << r << "\n";
        if(!g.is_ancestor(g.edge[x].second, r)){
            cout << "escaped\n";
            continue;
        }

        int h=g.tin[g.edge[x].first];
        int ans=g.down[r];
        int a=0;
        for(int j=l-1; j>=0; j--){
            if(g.up[r][j]==-1) continue;
            //cout << r << " " << j << " " << g.up[r][j] << " " << g.tin[g.up[r][j]] <<  " " << h << "\n";
            if(h<g.tin[g.up[r][j]]){
                //cout << "=> " << g.best[r][j] << " " << a << "\n";
                ans=min(ans, g.best[r][j]+a);
                a+=g.dist[r]-g.dist[g.up[r][j]];
                r=g.up[r][j];
            }
        }

        if(ans==inf){
            cout << "oo\n";
        }
        else{
            cout << ans << "\n";
        }
    }
}

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 340 KB Output is correct
2 Correct 3 ms 468 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 3 ms 460 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 340 KB Output is correct
2 Correct 3 ms 468 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 3 ms 460 KB Output is correct
5 Correct 2 ms 852 KB Output is correct
6 Correct 2 ms 852 KB Output is correct
7 Correct 2 ms 852 KB Output is correct
8 Correct 3 ms 852 KB Output is correct
9 Correct 2 ms 844 KB Output is correct
10 Correct 1 ms 852 KB Output is correct
11 Correct 3 ms 844 KB Output is correct
12 Correct 2 ms 852 KB Output is correct
13 Correct 2 ms 852 KB Output is correct
14 Correct 2 ms 904 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 154 ms 58480 KB Output is correct
2 Correct 205 ms 62156 KB Output is correct
3 Correct 203 ms 62536 KB Output is correct
4 Correct 269 ms 63548 KB Output is correct
5 Correct 230 ms 63780 KB Output is correct
6 Correct 294 ms 64924 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 340 KB Output is correct
2 Correct 3 ms 468 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 3 ms 460 KB Output is correct
5 Correct 2 ms 852 KB Output is correct
6 Correct 2 ms 852 KB Output is correct
7 Correct 2 ms 852 KB Output is correct
8 Correct 3 ms 852 KB Output is correct
9 Correct 2 ms 844 KB Output is correct
10 Correct 1 ms 852 KB Output is correct
11 Correct 3 ms 844 KB Output is correct
12 Correct 2 ms 852 KB Output is correct
13 Correct 2 ms 852 KB Output is correct
14 Correct 2 ms 904 KB Output is correct
15 Correct 154 ms 58480 KB Output is correct
16 Correct 205 ms 62156 KB Output is correct
17 Correct 203 ms 62536 KB Output is correct
18 Correct 269 ms 63548 KB Output is correct
19 Correct 230 ms 63780 KB Output is correct
20 Correct 294 ms 64924 KB Output is correct
21 Correct 163 ms 61860 KB Output is correct
22 Correct 199 ms 61612 KB Output is correct
23 Correct 188 ms 61808 KB Output is correct
24 Correct 263 ms 63304 KB Output is correct
25 Correct 273 ms 65236 KB Output is correct
26 Correct 160 ms 61888 KB Output is correct
27 Correct 187 ms 61792 KB Output is correct
28 Correct 227 ms 62028 KB Output is correct
29 Correct 240 ms 62956 KB Output is correct
30 Correct 315 ms 63960 KB Output is correct
31 Correct 161 ms 61952 KB Output is correct
32 Correct 171 ms 61736 KB Output is correct
33 Correct 192 ms 62088 KB Output is correct
34 Correct 284 ms 63332 KB Output is correct
35 Correct 275 ms 65064 KB Output is correct
36 Correct 231 ms 63144 KB Output is correct