Submission #917382

#	Time	Username	Problem	Language	Result	Execution time	Memory
917382		abcvuitunggio	Beech Tree (IOI23_beechtree)	C++17	9 / 100	2077 ms	37628 KiB

beechtree

#include "beechtree.h"
#include <bits/stdc++.h>
using namespace std;
int n,m,bad[200001],d[200001],p[200001][20],dp[2001][2001],ch[200001];
vector <pair <int, int>> ke[200001];
vector <int> res;
void dfs(int u){
    for (auto [c,v]:ke[u]){
        dfs(v);
        bad[u]|=bad[v];
    }
}
int lca(int u, int v){
    u++,v++;
    if (d[u]<d[v])
        swap(u,v);
    int x=d[u]-d[v];
    for (int i=0;i<20;i++)
        if ((x>>i)&1)
            u=p[u][i];
    if (u==v)
        return u-1;
    for (int i=19;i>=0;i--)
        if (p[u][i]!=p[v][i]){
            u=p[u][i];
            v=p[v][i];
        }
    return p[u][0]-1;
}
vector <int> beechtree(int N, int M, vector<int> P, vector<int> C){
    n=N,m=M;
    for (int i=1;i<n;i++)
        ke[P[i]].push_back({C[i],i});
    for (int i=0;i<n;i++){
        sort(ke[i].begin(),ke[i].end());
        for (int j=1;j<ke[i].size();j++)
            if (ke[i][j].first==ke[i][j-1].first)
                bad[i]=1;
        p[i+1][0]=P[i]+1;
        d[i+1]=d[P[i]+1]+1;
        for (int j=1;j<20;j++)
            p[i+1][j]=p[p[i+1][j-1]][j-1];
    }
    for (int i=0;i<n;i++)
        for (int j=i+1;j<n;j++){
            int u=i,v=j;
            if (ke[i].size()>ke[j].size())
                swap(u,v);
            for (auto [c,k]:ke[u])
                ch[c]=1;
            int cnt=0;
            for (auto [c,k]:ke[v])
                cnt+=ch[c];
            for (auto [c,k]:ke[u])
                ch[c]=0;
            if (cnt!=ke[u].size()){
                bad[lca(i,j)]=1;
                continue;
            }
            dp[i][j]=(ke[i].size()>ke[j].size()?1:(ke[i].size()<ke[j].size()?-1:0));
            if (!dp[i][j]){
                if (!i)
                    dp[i][j]=1;
                else if (C[i]==C[j])
                    dp[i][j]=dp[P[i]][P[j]];
            }
            if (dp[i][j]<0&&!i)
                bad[0]=1;
            if (dp[i][j]&&dp[i][j]==-dp[P[i]][P[j]]){
                int l=lca(i,j);
                if (l!=i)
                    bad[l]=1;
                else
                    bad[P[l]]=1;
            }
        }
    dfs(0);
    for (int i=0;i<n;i++)
        res.push_back(bad[i]^1);
    return res;
}

Compilation message (stderr)

beechtree.cpp: In function 'std::vector<int> beechtree(int, int, std::vector<int>, std::vector<int>)':
beechtree.cpp:36:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         for (int j=1;j<ke[i].size();j++)
      |                      ~^~~~~~~~~~~~~
beechtree.cpp:56:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |             if (cnt!=ke[u].size()){
      |                 ~~~^~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 9 / 9
• Subtask 2: 0 / 5
• Subtask 3: 0 / 9
• Subtask 4: 0 / 8
• Subtask 5: 0 / 14
• Subtask 6: 0 / 14
• Subtask 7: 0 / 12
• Subtask 8: 0 / 17
• Subtask 9: 0 / 12