Submission #941259

#	Time	Username	Problem	Language	Result	Execution time	Memory
941259		WanWan	Beech Tree (IOI23_beechtree)	C++17	0 / 100	75 ms	27224 KiB

beechtree

#include "beechtree.h"
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
void debug_out() {cerr<<endl;}
template <typename Head, typename... Tail>
void debug_out(Head _H, Tail... _T) {cerr<<" "<<to_string(_H);debug_out(_T...);}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:",debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif
const int MAXN = 200005;
const int inf=1000000500ll;
const long long oo =1000000000000000500ll;
const int MOD = (int)1e9+7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef pair<int,int> pi; 
int par[MAXN];
vector<int>childs[MAXN];
int st[MAXN],en[MAXN];
int TIME;
bool isleaf[MAXN];
bool child(int par, int child){
    if(st[par]<=st[child] && en[par]>=en[child])return 1;
    return 0;
}
void dfs(int x, int p){
    st[x]=TIME++;
    par[x]=p;
    isleaf[x]=1;
    for(auto v:childs[x]){
        isleaf[x]=0;
        dfs(v,x);
    }
    en[x]=TIME-1;
}
std::vector<int> beechtree(int n, int M, std::vector<int> P, std::vector<int> C)
{
    vector<int> res=vector<int>(n,0);
    for(int i=1;i<n;i++){
        childs[P[i]].push_back(i);
    }
    dfs(0,-1);
    for(int i=0;i<n;i++){ // check for this guy
        if(isleaf[i]){
            res[i]=1;
            continue;
        }
        int nonleafs=0;
        for(auto x:childs[i]){
            if(!isleaf[x])nonleafs++;
        }
        if(nonleafs>1){ 
            res[i]=0;
            continue;
        }
        int leaf=-1;
        for(auto x:childs[i]){
            if(!isleaf[x])leaf=x;
        }
        if(leaf == -1){
            // everyone is a leaf. just check that they are all different
            unordered_set<int>os;
            for(auto x:childs[i]){
                os.insert(C[x]);
            }
            if(os.size() == childs[i].size()){
                res[i]=1;
            } else{
                res[i]=0;
            }
        } else{
            // 1 leaf. 
            bool bad=0;
            unordered_set<int>ms;
            for(auto x:childs[i]){
                ms.insert(C[x]);
            }
            for(auto x:childs[leaf]){
                if(!isleaf[x])bad=1;
                if(ms.find(C[x]) == ms.end()){
                    bad=1;
                } else{
                }
            }
            
            if(!bad ){
                res[i]=1;
            }else{
                res[i]=0;
            }
        }
    }
    return res;
}

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