oj.uz

Submission #937713

# Submission time Handle Problem Language Result Execution time Memory
937713 2024-03-04T11:48:25 Z vjudge1 Valley (BOI19_valley) C++17
100 / 100
 316 ms 63692 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

# Verdict Execution time Memory Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 2 ms 348 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 2 ms 348 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 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 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 604 KB Output is correct
14 Correct 1 ms 860 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 139 ms 29508 KB Output is correct
2 Correct 171 ms 37908 KB Output is correct
3 Correct 211 ms 51360 KB Output is correct
4 Correct 255 ms 59764 KB Output is correct
5 Correct 228 ms 59732 KB Output is correct
6 Correct 313 ms 62700 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 2 ms 348 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 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 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 604 KB Output is correct
14 Correct 1 ms 860 KB Output is correct
15 Correct 139 ms 29508 KB Output is correct
16 Correct 171 ms 37908 KB Output is correct
17 Correct 211 ms 51360 KB Output is correct
18 Correct 255 ms 59764 KB Output is correct
19 Correct 228 ms 59732 KB Output is correct
20 Correct 313 ms 62700 KB Output is correct
21 Correct 125 ms 29784 KB Output is correct
22 Correct 146 ms 37428 KB Output is correct
23 Correct 167 ms 44012 KB Output is correct
24 Correct 233 ms 59476 KB Output is correct
25 Correct 304 ms 63692 KB Output is correct
26 Correct 119 ms 29812 KB Output is correct
27 Correct 153 ms 37208 KB Output is correct
28 Correct 175 ms 51268 KB Output is correct
29 Correct 239 ms 59404 KB Output is correct
30 Correct 316 ms 61372 KB Output is correct
31 Correct 138 ms 30032 KB Output is correct
32 Correct 154 ms 37968 KB Output is correct
33 Correct 188 ms 49488 KB Output is correct
34 Correct 271 ms 60496 KB Output is correct
35 Correct 284 ms 63516 KB Output is correct
36 Correct 279 ms 60752 KB Output is correct