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답안 #937711

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
937711 2024-03-04T11:47:31 Z naneosmic Valley (BOI19_valley) C++14
100 / 100
 357 ms 67012 KB 
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define int long long
#define endl "\n"
using namespace std;
vector<vector<pair<int,int>>>tree;
vector<bool>village;
vector<pair<int,int>>edges;
vector<int>depth;
vector<int>closest;
vector<int>visited;
vector<vector<pair<int,int>>>lifting;
vector<vector<int>>lifting2;
int n,e;
void dfs(int i,int k){
    if(visited[i]==true)return;
    visited[i]=true;
    depth[i]=k;
    int N=tree[i].size();
    for(int j=0;j<N;j++){
        dfs(tree[i][j].first,k+1);
    }
}
int dfs2(int i){
    if(visited[i]==true)return -1;
    visited[i]=true;
    int N=tree[i].size();
    int distance=LLONG_MAX;
    for(int j=0;j<N;j++){
        pair<int,int>a=tree[i][j];
        int current=dfs2(a.first);
        if(current!=-1&&current!=LLONG_MAX){
            current+=a.second;
            distance=min(current,distance);
        }
    }
    if(village[i]==true){
        return closest[i]=0;
    }
    closest[i]=distance;
    return distance;
}
void dfs3(int i,int p,int l){
    if(visited[i]==true)return;
    visited[i]=true;
    if(i!=e){
        pair<int,int>a=make_pair(p,l);
        int lim=1;
        while(lim<=depth[i]){
            lifting[i].push_back(a);
            int N1=lifting[i].size();
            int N2=lifting[a.first].size();
            if(N1<=N2){
                a.second+=lifting[a.first][N1-1].second;
                a.first=lifting[a.first][N1-1].first;
            }
            lim*=2;
        }
    }
    
    int N=tree[i].size();
    for(int j=0;j<N;j++){
        pair<int,int>a=tree[i][j];
        dfs3(a.first,i,a.second);
    }
}
int bit(int k){
    for(int i=62;i>=0;i--){
        if(((1LL<<i)&k)!=0){
            return i;
        }
    }
    return -1;
}
pair<int,int>lift(int i,int k){
    pair<int,int>ans;
    if(k==0){
        return make_pair(i,0);
    }else if(k==1){
        return lifting[i][0];
    }else{
        int l=bit(k);
        int b=(1LL<<l);
        ans=lifting[i][l];
        pair<int,int>c=lift(ans.first,k-b);
        ans.first=c.first;
        ans.second+=c.second;
    }
    return ans;
}
void dfs4(int i){
    if(visited[i]==true)return;
    visited[i]=true;
    if(i!=e){
        int ancestor=i;
        int a=closest[i];
        int lim=1;
        while(lim<=depth[i]){
            lifting2[i].push_back(a);
            int N1=lifting2[i].size();
            ancestor=lifting[i][N1-1].first;
            int val=lifting[i][N1-1].second;
            int N2=lifting2[ancestor].size();
            if(N1<=N2){
                int x=lifting2[ancestor][N1-1];
                if(x!=LLONG_MAX){
                    a=min(x+val,lifting2[i][N1-1]);
                }
            }
            lim*=2;
        }
    }
    int N=tree[i].size();
    for(int j=0;j<N;j++){
        pair<int,int>g=tree[i][j];
        dfs4(g.first);
    }
}
int end(int i,int k){
    int l=bit(k);
    int b=(1LL<<l);
    if(k==b){
        return lifting2[i][l];
    }
    int ans=lifting2[i][l];
    int NODE=lifting[i][l].first;
    int DIST=lifting[i][l].second;
    int sec=end(NODE,k-b);
    ans=min(ans,max(sec,sec+DIST));
    return ans;
}
void solve(){
    int r,i;
    cin>>r>>i;
    r--;
    i--;
    
    pair<int,int>edge=edges[r];
    int node;
    if(depth[edge.first]>depth[edge.second]){
        node=edge.first;
    }else{
        node=edge.second;
    }
    int d1=depth[i];
    int d2=depth[node];
    if(d1<d2){
        cout<<"escaped\n";
        return;
    }
    int dist=d1-d2;
    pair<int,int>par=lift(i,dist);
    if(par.first!=node){
        cout<<"escaped\n";
        return;
    }
    if(closest[node]==LLONG_MAX){
        cout<<"oo\n";
        return;
    }
    cout<<end(i,dist+1)<<endl;
    return;
}
signed main(){
    cin.tie(NULL);
    cout.tie(NULL);
    ios_base::sync_with_stdio(false);
    int s,q;
    cin>>n>>s>>q>>e;
    e--;
    tree.resize(n);
    edges.resize(n-1);
    village.resize(n,false);
    visited.resize(n,false);
    depth.resize(n);
    closest.resize(n);
    lifting.resize(n);
    lifting2.resize(n);
    for(int i=0;i<n-1;i++){
        int a,b,w;
        cin>>a>>b>>w;
        a--;
        b--;
        pair<int,int>a1=make_pair(a,w);
        pair<int,int>b1=make_pair(b,w);
        tree[a].push_back(b1);
        tree[b].push_back(a1);
        edges[i]=make_pair(a,b);
    }
    for(int i=0;i<s;i++){
        int a;
        cin>>a;
        a--;
        village[a]=true;
    }
    village[e]=true;
    dfs(e,0);
    for(int i=0;i<n;i++)visited[i]=false;
    dfs2(e);
    for(int i=0;i<n;i++)visited[i]=false;
    dfs3(e,0,0);
    for(int i=0;i<n;i++)visited[i]=false;
    dfs4(e);
    while(q--)solve();
}

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 600 KB Output is correct
2 Correct 2 ms 604 KB Output is correct
3 Correct 2 ms 604 KB Output is correct
4 Correct 2 ms 604 KB Output is correct

Subtask #2
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 600 KB Output is correct
2 Correct 2 ms 604 KB Output is correct
3 Correct 2 ms 604 KB Output is correct
4 Correct 2 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 832 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 860 KB Output is correct
11 Correct 1 ms 604 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 860 KB Output is correct
14 Correct 1 ms 860 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 135 ms 33388 KB Output is correct
2 Correct 197 ms 41836 KB Output is correct
3 Correct 210 ms 54936 KB Output is correct
4 Correct 247 ms 63220 KB Output is correct
5 Correct 243 ms 63516 KB Output is correct
6 Correct 297 ms 66604 KB Output is correct

Subtask #4
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 600 KB Output is correct
2 Correct 2 ms 604 KB Output is correct
3 Correct 2 ms 604 KB Output is correct
4 Correct 2 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 832 KB Output is correct
8 Correct 1 ms 600 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 860 KB Output is correct
11 Correct 1 ms 604 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 860 KB Output is correct
14 Correct 1 ms 860 KB Output is correct
15 Correct 135 ms 33388 KB Output is correct
16 Correct 197 ms 41836 KB Output is correct
17 Correct 210 ms 54936 KB Output is correct
18 Correct 247 ms 63220 KB Output is correct
19 Correct 243 ms 63516 KB Output is correct
20 Correct 297 ms 66604 KB Output is correct
21 Correct 119 ms 32900 KB Output is correct
22 Correct 152 ms 40720 KB Output is correct
23 Correct 191 ms 47272 KB Output is correct
24 Correct 221 ms 62908 KB Output is correct
25 Correct 278 ms 67012 KB Output is correct
26 Correct 126 ms 32852 KB Output is correct
27 Correct 150 ms 40276 KB Output is correct
28 Correct 175 ms 54456 KB Output is correct
29 Correct 244 ms 62544 KB Output is correct
30 Correct 357 ms 64880 KB Output is correct
31 Correct 142 ms 33052 KB Output is correct
32 Correct 181 ms 41296 KB Output is correct
33 Correct 222 ms 52800 KB Output is correct
34 Correct 266 ms 63568 KB Output is correct
35 Correct 349 ms 66888 KB Output is correct
36 Correct 268 ms 63572 KB Output is correct