Submission #475752

#	Time	Username	Problem	Language	Result	Execution time	Memory
475752		definitelynotmee	Papričice (COCI20_papricice)	C++98	110 / 110	214 ms	43000 KiB

papricice

#include<bits/stdc++.h>
#define mp make_pair
#define mt make_tuple
#define ff first
#define ss second
using namespace std;
template <typename T>
using matrix = vector<vector<T>>;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const ll INFL = (1LL<<62)-1;
const int INF = (1<<30)-1;
const double EPS = 1e-7;
const int MOD = 1e9 + 7;
const int MAXN = 1e6+1;



int main(){

    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    //ifstream cin("C:\\Users\\Leonardo\\Downloads\\contest1_testdata\\papricice\\papricice.in.2b");
    cin >> n;
    matrix<int> grafo(n+1);
    for(int i = 0; i < n-1; i++){
        int a, b;
        cin >> a >> b;
        grafo[a].push_back(b);
        grafo[b].push_back(a);
    }


    int resp = INF;
    vector<set<int>> vs(n+1);
    vector<int> sid(n+1);
    iota(sid.begin(),sid.end(),0);
    function<void(int,set<int>&)> getresp =[&](int c1,set<int>&s){
        if(s.size() == 0)
            return;
        int c2 = n-c1;
        auto it = s.lower_bound(c1>>1);

        resp = min(resp,(it==s.end() ? INF : max(c2,max(c1-*it,*it))-min(c2,min(c1-*it,*it))));

        if(it!=s.begin()){
            it--;
            resp = min(resp,(it==s.end() ? INF : max(c2,max(c1-*it,*it))-min(c2,min(c1-*it,*it))));
        }
    };
    function<int(int,int)> dfs = [&](int id, int last){
        
        int ret = 1;
        vector<int> csize(grafo[id].size());
        int mainset = -1;
        for(int i = 0; i < grafo[id].size(); i++){
            if(grafo[id][i]!=last){
                csize[i]=dfs(grafo[id][i],id);
                ret+=csize[i];
                if(vs[sid[grafo[id][i]]].size() > vs[sid[id]].size())
                    sid[id] = sid[grafo[id][i]], mainset = i;
            }
        }

        if(mainset != -1){
            getresp(csize[mainset],vs[sid[id]]);
            vs[sid[id]].insert(csize[mainset]);
        }
        for(int i = 0; i < grafo[id].size(); i++){
            if(grafo[id][i]!=last && i !=mainset){
                getresp(csize[i],vs[sid[grafo[id][i]]]);
                getresp(n-csize[i],vs[sid[id]]);
                for(int j : vs[sid[grafo[id][i]]]){
                    getresp(n-j,vs[sid[id]]);
                }
                for(int j : vs[sid[grafo[id][i]]]){
                    vs[sid[id]].insert(j);
                }
                vs[sid[id]].insert(csize[i]);
            }
        }
        
        //cout << "ret(" << id << ") = " << ret << ", resp = " << resp << '\n';
        return ret;
    };
    dfs(1,0);
    
    cout << resp << '\n';

    return 0;

}

Compilation message (stderr)

papricice.cpp: In lambda function:
papricice.cpp:59:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |         for(int i = 0; i < grafo[id].size(); i++){
      |                        ~~^~~~~~~~~~~~~~~~~~
papricice.cpp:72:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |         for(int i = 0; i < grafo[id].size(); i++){
      |                        ~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 60 / 60