Submission #303323

#	Time	Username	Problem	Language	Result	Execution time	Memory
303323		Vimmer	Connecting Supertrees (IOI20_supertrees)	C++14	0 / 100	1 ms	256 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];

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;
}

int construct(vector<vector<int> > p)
{
	int 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 (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 ((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;

            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;
    }

    return 0;
}

//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);
//}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:51:10: warning: variable 'f' set but not used [-Wunused-but-set-variable]
   51 |     bool f = 1, fr = 1, ft = 1;
      |          ^
supertrees.cpp:51:17: warning: variable 'fr' set but not used [-Wunused-but-set-variable]
   51 |     bool f = 1, fr = 1, ft = 1;
      |                 ^~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 10
• Subtask 3: 0 / 19
• Subtask 4: 0 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4