Submission #546332

#	Time	Username	Problem	Language	Result	Execution time	Memory
546332		Jarif_Rahman	Jail (JOI22_jail)	C++17	72 / 100	3870 ms	1048576 KiB

jail

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

const int K = 19;
 
int n, m;
vector<vector<int>> v;
vector<int> s, t;
vector<vector<int>> sth;
vector<int> state;
vector<int> anc[K];
vector<int> d;
bool cycle;
 
void dfs1(int nd, int ss, int dis){
    for(int x: v[nd]) if(x != ss) dfs1(x, nd, dis+1);
    if(ss != -1) anc[0][nd] = ss;
    d[nd] = dis;
}

int get_anc(int nd, int h){
    for(int i = 0; i < K; i++){
        if(h%2 == 1) nd = anc[i][nd];
        h/=2;
    }
    return nd;
}
 
int lca_jump(int a, int b){
    if(a == b) return a;
    for(int i = K-1; i >= 0; i--) if(anc[i][a] != anc[i][b])
        return lca_jump(anc[i][a], anc[i][b]);
    return anc[0][a];
}
 
int lca(int a, int b){
    if(d[b] < d[a]) swap(a, b);
    b = get_anc(b, d[b]-d[a]);
    return lca_jump(a, b);
}

int fix_path(int a, int b){
    if(lca(a, b) == a) return get_anc(b, d[b]-d[a]-1);
    return anc[0][a];
}


void dfs2(int nd){
    if(state[nd] == 1){
        cycle = 1;
        return;
    }
    if(state[nd] == 2) return;
    state[nd] = 1;
    for(int x: sth[nd]) dfs2(x);
    state[nd] = 2;
}
 
void solve(){
    cin >> n;
    v.assign(n, {});
    fill(anc, anc+K, vector<int>(n, 0));

    d.assign(n, 0);
    sth.assign(2*n, {});
    state.assign(2*n, 0);

    for(int i = 0; i < n-1; i++){
        int a, b; cin >> a >> b; a--, b--;
        v[a].pb(b);
        v[b].pb(a);
    }
 
    dfs1(0, -1, 0);
    for(int p = 1; p < K; p++) for(int i = 0; i < n; i++)
        anc[p][i] = anc[p-1][anc[p-1][i]];
 
    cin >> m;
    s.assign(m, 0);
    t.assign(m, 0);
    for(int i = 0; i < m; i++) cin >> s[i] >> t[i], s[i]--, t[i]--;
    for(int i = 0; i < m; i++){
        sth[s[i]].pb(t[i]+n);
    }
  
    auto get_path = [&](int a, int b){
        vector<int> rt;
        if(d[a] > d[b]) swap(a, b);
        while(d[a] != d[b]) rt.pb(b), b = anc[0][b];
        while(a != b) rt.pb(a), rt.pb(b), a = anc[0][a], b = anc[0][b];
        rt.pb(a);
        return rt;
    };
 
    for(int i = 0; i < m; i++){
        for(int x: get_path(fix_path(s[i], t[i]), t[i])) sth[t[i]+n].pb(x);
        for(int x: get_path(s[i], fix_path(t[i], s[i]))) sth[x+n].pb(s[i]);
    }
 
    cycle = 0;
 
    for(int i = 0; i < 2*n; i++) if(state[i] == 0) dfs2(i);
 
    cout << (cycle?"No\n":"Yes\n");
}
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int T; cin >> T; while(T--) solve();
}

• Subtask 1: 0 / 5
• Subtask 2: 5 / 5
• Subtask 3: 16 / 16
• Subtask 4: 28 / 28
• Subtask 5: 12 / 12
• Subtask 6: 11 / 11
• Subtask 7: 0 / 23