Submission #938539

#	Time	Username	Problem	Language	Result	Execution time	Memory
938539		groshi	Mergers (JOI19_mergers)	C++17	100 / 100	964 ms	204708 KiB

mergers

#include<bits/stdc++.h>
using namespace std;
#define int long long
struct wi{
    vector<int> Q;
    int kolor=0;
    int zle=0;
    int gore=0;
    int suma=0;
}*w;
int ile[600000];
map<int,int> mapka[600000];
int wynik=0;
int wszyscy=0;
void dfs(int x,int ojc)
{
    mapka[x][w[x].kolor]++;
    if(ile[w[x].kolor]==1)
        mapka[x].erase(w[x].kolor);
    for(int i=0;i<w[x].Q.size();i++)
    {
        int pom=w[x].Q[i];
        if(pom==ojc)
            continue;
        dfs(pom,x);
        if(mapka[pom].size()>mapka[x].size())
            swap(mapka[pom],mapka[x]);
        for(auto it=mapka[pom].begin();it!=mapka[pom].end();it++)
        {
            mapka[x][it->first]+=it->second;
            if(mapka[x][it->first]==ile[it->first])
                mapka[x].erase(it->first);
        }
    }
    if(mapka[x].size()==0 && x!=1)
        w[x].zle=1,w[ojc].zle=1;
}
void dfs2(int x,int ojc)
{
    w[x].suma+=w[x].zle;
    int teraz=0;
    for(int i=0;i<w[x].Q.size();i++)
    {
        int pom=w[x].Q[i];
        if(pom==ojc)
            continue;
        dfs2(pom,x);
        w[x].suma+=w[pom].suma;
        if(w[pom].suma>=1)
            teraz++;
    }
    //cout<<x<<": "<<w[x].suma<<" "<<wszyscy<<" "<<teraz<<"\n";
    if(w[x].suma==1 && w[x].zle==1)
        wynik++;
    else if(w[x].suma==wszyscy && teraz==1 && w[x].zle==1)
        wynik++;
}
int32_t main()
{
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(0);
    int n,k,x,y;
    cin>>n>>k;
    w=new wi[n+3];
    for(int i=1;i<n;i++)
    {
        cin>>x>>y;
        w[x].Q.push_back(y);
        w[y].Q.push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        cin>>x;
        ile[x]++;
        w[i].kolor=x;
    }
    dfs(1,0);
    for(int i=1;i<=n;i++)
        wszyscy+=w[i].zle;
    dfs2(1,0);
    //cout<<wynik<<"\n";
    cout<<(wynik+1)/2;
    return 0;
}

Compilation message (stderr)

mergers.cpp: In function 'void dfs(long long int, long long int)':
mergers.cpp:20:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for(int i=0;i<w[x].Q.size();i++)
      |                 ~^~~~~~~~~~~~~~
mergers.cpp: In function 'void dfs2(long long int, long long int)':
mergers.cpp:42:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     for(int i=0;i<w[x].Q.size();i++)
      |                 ~^~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 24 / 24
• Subtask 3: 14 / 14
• Subtask 4: 22 / 22
• Subtask 5: 30 / 30