Submission #1033962

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033962		vjudge1	Meetings 2 (JOI21_meetings2)	C++17	0 / 100	1 ms	10588 KiB

meetings2

#include<bits/stdc++.h>
#define int long long
#define ll pair<int,int>
using namespace std;

const int N=200022;
vector<int> ke[N];
int maxx[N];
int h[N];
int kq[N];
int oo=1e9;
int kq2[N];
int sz[N];

void dfs(int u,int pa)
{
    sz[u]=1;
    for (int i=0;i<ke[u].size();i++)
    {
        int v=ke[u][i];
        if (v==pa) continue;
        dfs(v,u);
        sz[u]+=sz[v];
    }
}

int dfs2(int u,int pa,int kk)
{
    for (int i=0;i<ke[u].size();i++)
    {
        int v=ke[u][i];
        if (v==pa) continue;
        if (sz[v]>kk/2) return dfs2(v,u,kk);
    }
    return u;
}

void dfs3(int u,int pa,int kk)
{
    sz[u]=1;
    h[u]=kk;
    for (int i=0;i<ke[u].size();i++)
    {
        int v=ke[u][i];
        if (v==pa) continue;
        dfs3(v,u,kk+1);
        sz[u]+=sz[v];
    }
    kq[sz[u]]=max(kq[sz[u]],h[u]);
}

signed main()
{
    // freopen("kk.inp","r",stdin);
    // freopen("kk.out","w",stdout);
    // freopen("City.inp","r",stdin);
    // freopen("City.out","w",stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    int n;
    cin >> n;
    for (int i=1;i<n;i++)
    {
        int u,v;
        cin >> u >> v;
        ke[u].push_back(v);
        ke[v].push_back(u);
    }
    dfs(1,0);
    int dinh=dfs2(1,0,sz[1]);
    h[dinh]=0;
    for (int i=1;i<=n;i++) kq[i]=maxx[i]=-oo;
    for (int i=0;i<ke[dinh].size();i++)
    {
        int v=ke[dinh][i];
        dfs3(v,dinh,1);
        kq[sz[v]+1]=0;
        for (int i2=sz[v]+1;i2>=2;i2--) kq[i2-1]=max(kq[i2-1],kq[i2]);
        for (int i2=1;i2<=sz[v]+1;i2++)
        {
            kq2[i2*2]=max(kq2[i2*2],kq[i2]+maxx[i2]);
        }
        for (int i2=1;i2<=sz[v]+1;i2++) 
        {
            maxx[i2]=max(maxx[i2],kq[i2]);
            kq[i2]=-oo;
        }
    }
    for (int i=1;i<=n;i++)
    {
        cout << kq2[i]+1 << '\n';
    }
}

Compilation message (stderr)

meetings2.cpp: In function 'void dfs(long long int, long long int)':
meetings2.cpp:18:19: 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]
   18 |     for (int i=0;i<ke[u].size();i++)
      |                  ~^~~~~~~~~~~~~
meetings2.cpp: In function 'long long int dfs2(long long int, long long int, long long int)':
meetings2.cpp:29:19: 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]
   29 |     for (int i=0;i<ke[u].size();i++)
      |                  ~^~~~~~~~~~~~~
meetings2.cpp: In function 'void dfs3(long long int, long long int, long long int)':
meetings2.cpp:42:19: 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<ke[u].size();i++)
      |                  ~^~~~~~~~~~~~~
meetings2.cpp: In function 'int main()':
meetings2.cpp:74:19: 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]
   74 |     for (int i=0;i<ke[dinh].size();i++)
      |                  ~^~~~~~~~~~~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 16
• Subtask 3: 0 / 80