Submission #1024965

#	Time	Username	Problem	Language	Result	Execution time	Memory
1024965		Mardonbekhazratov	Beech Tree (IOI23_beechtree)	C++17	14 / 100	62 ms	21712 KiB

beechtree

#include "beechtree.h"
#include <algorithm>
#include <map>

using namespace std;

int n,m;
vector<int>p,c,ans,depth;
vector<vector<int>>v;

vector<int>subtree;

void dfs(int x){
    subtree.push_back(x);
    for(int z:v[x]){
        dfs(z);
    }
}

bool check(vector<int>s){
    map<int,int>m;
    for(int i=1;i<s.size();i++){
        if(s[m[c[s[i]]]]!=p[s[i]]) return false;
        m[c[s[i]]]++;
    }
    return true;
}

void sub1(){
    for(int i=0;i<n;i++){
        dfs(i);
        sort(subtree.begin(),subtree.end());
        do{
            if(check(subtree)){
                ans[i]=1;
                break;
            }
        }while(next_permutation(subtree.begin(),subtree.end()));
        subtree.clear();
    }
}

void sub2(){
    ans[n-1]=ans[n-2]=1;
    int j=n-2;
    while(j>0 && c[j]==c[j+1]){
        ans[--j]=1;
    }
}

void sub3(){
    vector<vector<int>>cnt(m+1);
    int k=0,g=0;
    for(int i=1;i<n;i++){
        if(depth[i]==2) g=i,k++;
        cnt[c[i]].push_back(i);
        dfs(i);
        ans[i]=check(subtree);
        vector<int>ev;
        swap(ev,subtree);
    }
    for(int i=1;i<=m;i++){
        if(i!=c[g] && cnt[c[i]].size()>1) return;
    }
    if(k>1) return;
    ans[0]=1;
    // vector<bool>vis(n,false);
    // subtree.push_back(0);
    // if(g>0){
    //     subtree.push_back(p[g]);
    //     if(cnt[c[g]][0]!=p[g]) subtree.push_back(cnt[c[g]][0]);
    // }
    // for(int x:subtree) vis[x]=true;
}

void dfs(int x,int c){
    depth[x]=c;
    for(int z:v[x]){
        dfs(z,c+1);
    }
}

vector<int> beechtree(int N, int M, std::vector<int> P, std::vector<int> C){
    n=N,m=M;
    swap(p,P);
    swap(c,C);
    v.resize(n);
    bool sui2=true;
    for(int i=1;i<n;i++){
        if(p[i]!=i-1) sui2=false;
        v[p[i]].push_back(i);
    }
    ans.assign(n,0);
    depth.resize(n);
    dfs(0,0);
    if(n<=8) sub1();
    else if(sui2) sub2();
    else sub3();
    return ans;
}

Compilation message (stderr)

beechtree.cpp: In function 'bool check(std::vector<int>)':
beechtree.cpp:22:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     for(int i=1;i<s.size();i++){
      |                 ~^~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 9 / 9
• Subtask 2: 5 / 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