Submission #998384

#	Time	Username	Problem	Language	Result	Execution time	Memory
998384		andrei_iorgulescu	Newspapers (CEOI21_newspapers)	C++14	0 / 100	5 ms	27740 KiB

newspapers

#include <bits/stdc++.h>

using namespace std;

ifstream in("lol.in");
ofstream out("lol.out");

int n;
int m;
vector<int> g[25];
vector<int> gmask[(1 << 20) + 5];
int t[(1 << 20) + 5];

bool pot[(1 << 20) + 5];

void dfs(int mask)
{
    pot[mask] = true;
    for (auto vecin : gmask[mask])
        if (!pot[vecin])
            t[vecin] = mask,dfs(vecin);
}

int main()
{
    cin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x,y;
        cin >> x >> y;
        x--;
        y--;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    if (m != n - 1)
    {
        cout << "NO";
        return 0;
    }
    for (int mask = 1; mask < (1 << n); mask++)
    {
        for (int bit = 0; bit < n; bit++)
        {
            if (mask & (1 << bit))
            {
                bool huh[25];
                for (int i = 0; i < n; i++)
                {
                    if (i == bit or !(mask & (1 << i)))
                        huh[i] = true;
                    else
                        huh[i] = false;
                }
                int new_mask = 0;
                for (int i = 0; i < n; i++)
                {
                    bool iau = false;
                    for (auto vecin : g[i])
                        if (huh[vecin] == false)
                            iau = true;
                    if (iau)
                        new_mask += (1 << i);
                }
                gmask[new_mask].push_back(mask);
            }
        }
    }
    dfs(0);
    if (pot[(1 << n) - 1])
    {
        cout << "YES\n\n";
        /*int x = (1 << n) - 1;
        while (x != 0)
        {
            cout << x << endl;
            x = t[x];
        }*/
    }
    else
        cout << "NO";
    return 0;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 8
• Subtask 3: 0 / 80