oj.uz

Submission #547126

# Submission time Handle Problem Language Result Execution time Memory
547126 2022-04-09T16:00:40 Z byunjaewoo Mergers (JOI19_mergers) C++17
0 / 100
 123 ms 71132 KB 
#include <bits/stdc++.h>
using namespace std;

const int Nmax=500010;
int N, K, S[Nmax], L[Nmax], Dep[Nmax], P[Nmax][20], G[Nmax], ind[Nmax], ans;
vector<int> adj[Nmax], V[Nmax];
set<int> cadj[Nmax];

int Find(int x) {return G[x]?(G[x]=Find(G[x])):x;}
void Union(int a, int b) {
    a=Find(a), b=Find(b);
    if(a!=b) G[a]=b;
}

void DFS(int curr, int prev) {
    for(int next:adj[curr]) if(next!=prev) {
        Dep[next]=Dep[curr]+1;
        P[next][0]=curr;
        DFS(next, curr);
    }
}

int LCA(int u, int v) {
    if(Dep[u]<Dep[v]) swap(u, v);
    int dif=Dep[u]-Dep[v];
    for(int i=0; dif; i++) {
        if(dif&1) u=P[u][i];
        dif>>=1;
    }
    if(u!=v) {
        for(int i=19; i>=0; i--) {
            if(P[u][i] && P[u][i]!=P[v][i]) u=P[u][i], v=P[v][i];
        }
        u=P[u][0];
    }
    return u;
}

void DFS2(int curr, int prev) {
    for(int i=curr; Dep[i]>Dep[L[S[curr]]]; i=L[S[P[i][0]]]) {
        Union(i, P[i][0]);
    }
    for(int next:adj[curr]) if(next!=prev) DFS2(next, curr);
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>N>>K;
    for(int i=1; i<N; i++) {
        int u, v; cin>>u>>v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for(int i=1; i<=N; i++) {
        cin>>S[i];
        V[S[i]].push_back(i);
    }
    DFS(1, 0);
    for(int i=1; i<=20; i++) {
        for(int j=1; j<=N; j++) P[j][i]=P[P[j][i-1]][i-1];
    }
    for(int i=1; i<=K; i++) {
        for(int j:V[i]) {
            if(!L[i]) {L[i]=j; continue;}
            L[i]=LCA(L[i], j);
        }
    }
    DFS2(1, 0);
    for(int i=1; i<=N; i++) Find(i);
    for(int i=1; i<=N; i++) if(!G[i]) G[i]=i;
    for(int i=1; i<=N; i++) {
        for(int j:adj[i]) if(G[i]!=G[j]) cadj[G[i]].insert(G[j]);
    }
    for(int i=1; i<=N; i++) ans+=(cadj[i].size()==1);
    cout<<(ans+1)/2;
    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 47316 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 47316 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 47316 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 123 ms 71132 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 47316 KB Output isn't correct
2 Halted 0 ms 0 KB -