Submission #955988

#	Time	Username	Problem	Language	Result	Execution time	Memory
955988		shezitt	Papričice (COCI20_papricice)	C++17	50 / 110	63 ms	6748 KiB

papricice

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>

using namespace std;

using ll = long long;

#define int ll
#define fore(i, a, b) for(int i=a; i<b; ++i)
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define pb(x) push_back(x)
#define vi vector<int>

const int N = 2005;

vi adj[N];

int n;

/*int taken[N];

int dfs(int x, int prev=-1){
    int tam = 1;

    for(int child : adj[x]){
        if(child == prev) continue;
        tam += dfs(child, x);
    }

    if(taken[x]){

        taken[x] = tam;

        tam = 0;
    }   

    return tam;

}*/

int tam[N];
int pa[N];

void dfs(int x, int prev=-1){
    tam[x] = 1;
    pa[x] = prev;
    for(int child : adj[x]){
        if(child == prev) continue;
        dfs(child, x);
        tam[x] += tam[child];
    }
}

set<pair<int,int>> parientes;

void calcParientes(int start, int x, int prev=-1){
    if(start != x){
        parientes.insert(make_pair(min(start, x), max(start, x)));
    }
    for(int child : adj[x]){
        if(child == prev) continue;
        calcParientes(start, child, x);
    }
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> n;
/*
    if(n <= 200){
        fore(i, 0, n-1){
            int u, v;
            cin >> u >> v;
            adj[u].pb(v);
            adj[v].pb(u);
        }

        int ans = 1e9;

        taken[1] = 1;

        for(int i=2; i<=n; ++i){
            for(int j=i+1; j<=n; ++j){
                taken[1] = taken[i] = taken[j] = 1;

                dfs(1);
                ans = min(ans, max({taken[1],taken[i],taken[j]}) - min({taken[1],taken[i],taken[j]}));

                taken[1] = taken[i] = taken[j] = 0;
            }
        }

        cout << ans;

        return 0;

    }
*/

    if(n <= 2000){

        fore(i, 0, n-1){
            int u, v;
            cin >> u >> v;
            adj[u].pb(v);
            adj[v].pb(u);
        }

        int ans = 1e9;

        dfs(1);

        fore(i, 1, n+1){
            calcParientes(i, i, pa[i]);
        }

        fore(i, 2, n+1){
            fore(j, i+1, n+1){

                int p = i;
                int q = j;

                if(tam[p] > tam[q]) swap(p, q);

                int tam1 = tam[p];
                int tam2 = tam[q];
                if(parientes.count({min(p, q), max(p, q)})){
                    tam2 -= tam1;
                }
                int tam3 = n - tam1 - tam2;

                ans = min(ans, max({tam1, tam2, tam3}) - min({tam1, tam2, tam3}));

            }
        }

        cout << ans;

        return 0;
    }


}

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 0 / 60