Submission #825365

#	Time	Username	Problem	Language	Result	Execution time	Memory
825365		HorizonWest	Connecting Supertrees (IOI20_supertrees)	C++17	21 / 100	165 ms	26080 KiB

supertrees

#include <bits/stdc++.h>
using namespace std;

#define endl '\n'
#define db double
#define ll __int128
//#define int long long
#define pb push_back
#define fs first
#define sd second
#define Mod long(1e9 + 7)
#define all(x) x.begin(), x.end()
#define unvisited long(-1)
#define Eps double(1e-9)
#define _for(i, n) for(int i = 0; i < (n); i++)
#define dbg(x) cout << #x ": " << x << endl;

const int Max = 1e6 + 7, Inf = 1e9 + 7;

void build(std::vector<std::vector<int>> b);

struct DSU
{
    vector <int> link, size;

    int find(int x)
    {
        while(x != link[x]) x = link[x];
        return x;
    }

    int sz(int x)
    {
        return size[find(x)];
    }

    bool same(int a, int b)
    {
        return find(a) == find(b);
    }

    void unite(int a, int b)
    {
        a = find(a); b = find(b);
        if(a == b) return;
        if(size[a] < size[b]) swap(a, b);
        link[b] = a; size[a] += size[b];
    }

    DSU(int n)
    {
        link.assign(n+1, 0);
        size.assign(n+1, 1);
        for(int i = 0; i <= n; i++)
            link[i] = i;
    }
};

int construct(std::vector<std::vector<int>> p)
{
    int n = p.size(); DSU St(n), Fx(n);

    vector <vector<int>> g(n, vector <int> (n, 0)),
                        ans(n, vector <int> (n, 0));

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++) if(j != i)
        {
            if(p[i][j] != p[j][i] || p[i][j] == 3)
                return 0;

            if(p[i][j] != 0)
                St.unite(i, j);
        }
    }

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
            if(St.same(i, j) && p[i][j] == 0 && i != j) return 0;
    }

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
        {
            if(p[i][j] == 1 && !Fx.same(i, j))
            {
                Fx.unite(i, j);
                ans[i][j] = ans[j][i] = 1;
            }
        }
    }

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
            if(Fx.same(i, j) && p[i][j] == 2) return 0;
    }

    map <int, int> mp;

    for(int i = 0; i < n; i++)
    {
        if(mp[St.find(i)]) continue;
        mp[St.find(i)] = 1;

        vector <int> s;

        for(int j = 0; j < n; j++)
        {
            if(St.same(i, j) && St.find(j) == j)
            {
                s.push_back(j);
            }
        }
        int m = s.size();

        if(m > 1)
        for(int i = 0; i < m; i++)
            ans[s[i]][s[(i+1)%m]] = ans[s[(i+1)%m]][s[i]] = 1;
    }

    build(ans);
    return 1;
}

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