Submission #303375

#	Time	Username	Problem	Language	Result	Execution time	Memory
303375		Vimmer	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	282 ms	26288 KiB

supertrees

#include <bits/stdc++.h>
#include "supertrees.h"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

#define N 1005
#define PB push_back
#define sz(x) int(x.size())
#define P 31
#define F first
#define M ll(1e9 + 7)
#define S second
#define all(x) x.begin(), x.end()
#define endl '\n'

//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;

//typedef tree<int, null_type, less_equal <int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

ll mlt(ll a, ll b) {return (a * b) % M;}
ll sm(ll a, ll b) {return (a + b) % M;}

int rk[N], pr[N], cnt[N][N], n, glob;

bool mk[N];

vector <int> g[N];

void make(int x) {pr[x] = x; rk[x] = 1;}
int fnd(int x) {if (pr[x] != x) pr[x] = fnd(pr[x]); return pr[x];}
void link(int a, int b)
{
    if (rk[b] > rk[a]) swap(a, b);

    rk[a] += rk[b];

    pr[b] = a;
}

//void build(vector <vector <int> > pr)
//{
//    for (int i = 0; i < sz(pr); i++)
//    {
//        cout << i << ": ";
//
//        for (auto itr : pr[i]) cout << itr << " "; cout << endl;
//    }
//}

void dfs(int v, int p)
{
    mk[v] = 1;

    cnt[glob][v]++;

    for (auto it : g[v])
      if (!mk[it]) dfs(it, v);

    mk[v] = 0;
}

int construct(vector<vector<int> > p)
{
	n = sz(p);

	vector<vector<int> > answer; answer.clear();

    bool f = 1, fr = 1, ft = 1;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (i != j) {if (p[i][j] == 2 || p[i][j] == 3) fr = 0; if (p[i][j] != 1) f = 0; if (p[i][j] == 1 || p[i][j] == 3) ft = 0;}

    if (f)
    {
        answer.resize(n);

        for (int i = 0; i < n; i++)
            answer[i].resize(n, 0);

        for (int i = 1; i < n; i++) answer[0][i] = 1;

        for (int i = 1; i < n; i++) answer[i][0] = 1;

        build(answer);

        return 1;
    }

    if (fr)
    {
        bool good = 1;

        answer.resize(n);

        for (int i = 0; i < n; i++)
            answer[i].resize(n, 0);

        for (int i = 0; i < n; i++) make(i);

        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                if (p[i][j] == 1)
                    {
                        int a = fnd(i), b = fnd(j);

                        if (a != b) {answer[i][j] = answer[j][i] = 1; link(a, b);}
                    }

        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
              if ((p[i][j] == 1 && fnd(i) != fnd(j)) || (p[i][j] == 0 && fnd(i) == fnd(j))) good = 0;

        if (good) build(answer);

        return good;
    }

    if (ft)
    {
        bool good = 1;

        answer.resize(n);

        for (int i = 0; i < n; i++)
            answer[i].resize(n, 0);

        for (int i = 0; i < n; i++) make(i);

        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                if (p[i][j] == 2)
                    {
                        int a = fnd(i), b = fnd(j);

                        if (a != b) link(a, b);
                    }

        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
              if (i != j && ((p[i][j] == 2 && fnd(i) != fnd(j)) || (p[i][j] == 0 && fnd(i) == fnd(j)))) good = 0;

        if (!good) return 0;

        set <int> se; se.clear();

        for (int i = 0; i < n; i++)
        {
            int id = fnd(i);

            if (se.find(id) != se.end()) continue;

            se.insert(id);

            vector <int> pr; pr.clear();

            for (int j = 0; j < n; j++)
                if (fnd(j) == id)
                  pr.PB(j);

            if (sz(pr) == 1) continue;

            if (sz(pr) == 2) {good = 0; break;}

            for (int j = 0; j < sz(pr); j++)
            {
                int nxt = (j + 1) % sz(pr);

                answer[pr[j]][pr[nxt]] = answer[pr[nxt]][pr[j]] = 1;
            }
        }

        if (!good) return 0;

        build(answer);

        return 1;
    }

    bool good = 1;

    answer.resize(n);

    for (int i = 0; i < n; i++)
        answer[i].resize(n, 0);

    for (int i = 0; i < n; i++) make(i);

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (p[i][j] == 1 || p[i][j] == 2)
                {
                    int a = fnd(i), b = fnd(j);

                    if (a != b) link(a, b);
                }

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
          if ((p[i][j] == 1 && fnd(i) != fnd(j)) || (p[i][j] == 0 && fnd(i) == fnd(j))) good = 0;

    if (!good) return 0;

    bool mk[n], mkr[n];

    for (int i = 0; i < n; i++)
    {
        mk[i] = 1;

        mkr[i] = 1;

        for (int j = 0; j < n; j++)
            if (i != j && p[i][j] == 1) mk[i] = 0;

        for (int j = 0; j < n; j++)
            if (i != j && p[i][j] == 2) mkr[i] = 0;
    }

    set <int> se, str; se.clear(); str.clear();

    for (int i = 0; i < n; i++)
    {
        int id = fnd(i);

        if (se.find(id) != se.end()) continue;

        se.insert(id);

        vector <int> c; c.clear();

        vector <int> pr; pr.clear();

        bool bd = 1;

        for (int j = 0; j < n; j++)
        {
            if (fnd(j) != fnd(i)) continue;

            if (mk[j]) c.PB(j);
              else pr.PB(j);

            if (!mkr[j]) bd = 0;
        }

        if (sz(c) == 0)
        {
            if (bd)
            {
                for (int j = 1; j < sz(pr); j++)
                {
                    int nxt = pr[j - 1];

                    answer[pr[j]][nxt] = answer[nxt][pr[j]] = 1;
                }

                continue;
            }

            int l = -1, r = -1;

            for (int j = 0; j < sz(pr); j++)
            {
                auto it = pr[j];

                if (str.find(it) != str.end()) continue;

                str.insert(it);

                if (r != -1) answer[r][it] = answer[it][r] = 1;
                  else l = it;

                r = it;

                int lst = it;

                for (int u = j + 1; u < sz(pr); u++)
                    if (p[pr[u]][it] == 1)
                    {
                        str.insert(pr[u]);

                        answer[pr[u]][lst] = answer[lst][pr[u]] = 1;

                        lst = pr[u];
                    }
            }

            answer[l][r] = answer[r][l] = 1;

            continue;
        }

        for (int j = 1; j < sz(c); j++) answer[c[j]][c[j - 1]] = answer[c[j - 1]][c[j]] = 1;

        int l = c[0], r = c.back();

        for (int j = 0; j < sz(pr); j++)
        {
            auto it = pr[j];

            if (str.find(it) != str.end()) continue;

            str.insert(it);

            answer[l][it] = answer[it][l] = 1;

            l = it;

            int lst = it;

            for (int u = j + 1; u < sz(pr); u++)
                if (p[pr[u]][it] == 1)
                {
                    str.insert(pr[u]);

                    answer[pr[u]][lst] = answer[lst][pr[u]] = 1;

                    lst = pr[u];
                }
        }

        answer[l][r] = answer[r][l] = 1;
    }

    for (int i = 0; i < n; i++) answer[i][i] = 0;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++) if (answer[i][j] == 1) g[i].PB(j);

    for (int i = 0; i < n; i++)
    {
        glob = i;

        dfs(i, -1);

        for (int j = 0; j < n; j++)
            if (cnt[i][j] != p[i][j]) return 0;
    }

    build(answer);

    return 1;
}

//int main()
//{
////    freopen("help.in", "r", stdin); freopen("help.out", "w", stdout);
//
//    ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//
//    vector <vector <int> > vr(6);
//
//    for (int i = 0; i < 6; i++) {vr[i].resize(6, 0); vr[i][i] = 1;}
//
//    vr[0][3] = vr[3][0] = vr[2][4] = vr[4][2] = vr[1][5] = vr[5][1] = 1;
//
//    for (int i = 0; i < 6; i++)
//        for (int j = 0; j < 6; j++)
//          if (vr[i][j] != 1) vr[i][j] = 2;
//
//    cout << construct(vr) << endl;
//}

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 21 / 21
• Subtask 6: 4 / 4