Submission #1094926

#	Time	Username	Problem	Language	Result	Execution time	Memory
1094926		raphaelp	Make them Meet (EGOI24_makethemmeet)	C++14	34 / 100	5 ms	864 KiB

Main

#include <bits/stdc++.h>
using namespace std;
class UnionFind
{
private:
    vector<int> p;

public:
    UnionFind(int x)
    {
        p.assign(x, 0);
        for (int i = 0; i < x; i++)
            p[i] = i;
    }
    int find(int x) { return (x == p[x]) ? x : p[x] = find(p[x]); }
    bool merge(int a, int b)
    {
        int x = find(a), y = find(b);
        if (x == y)
            return 0;
        p[x] = y;
        return 1;
    }
};
void dfs(int x, int p, vector<vector<int>> &AR, vector<vector<int>> &ans, int &cur, int &last)
{
    if (x != last)
    {
        ans[cur][x] = last;
        cur++;
        last = x;
    }
    for (int i = 0; i < AR[x].size(); i++)
    {
        if (AR[x][i] == p)
            continue;
        dfs(AR[x][i], x, AR, ans, cur, last);
        ans[cur][x] = last;
        cur++;
        last = x;
    }
}
void dfs2(int x, int p, vector<vector<int>> &AR, vector<int> &par, vector<int> &deb, vector<int> &sub, int &cur, int depth, int tree)
{
    sub[x] = tree;
    par[x] = p;
    deb[x] = cur - depth;
    cur += 2;
    for (int i = 0; i < AR[x].size(); i++)
    {
        if (AR[x][i] == p)
            continue;
        dfs2(AR[x][i], x, AR, par, deb, sub, cur, depth + 1, tree);
    }
}
void dfs3(int x, vector<int> &occ, vector<vector<int>> &AR, int &num, int nono)
{
    num++;
    occ[x] = 1;
    for (int i = 0; i < AR[x].size(); i++)
    {
        if (occ[AR[x][i]])
            continue;
        if (AR[x][i] == nono)
            continue;
        dfs3(AR[x][i], occ, AR, num, nono);
    }
}

int main()
{
    int N, M;
    cin >> N >> M;
    vector<vector<int>> AR(N), AR2(N);
    UnionFind UF(N);
    for (int i = 0; i < M; i++)
    {
        int a, b;
        cin >> a >> b;
        AR2[a].push_back(b);
        AR2[b].push_back(a);
    }
    int centre = -1, leaf = -1;
    vector<int> banned(N);
    for (int i = 0; i < N; i++)
    {
        if (centre != -1)
            break;
        for (int j = 0; j < N; j++)
        {
            if (centre != -1)
                break;
            vector<int> temp(N);
            for (int k = 0; k < AR2[i].size(); k++)
                temp[AR2[i][k]] = 1;
            for (int k = 0; k < AR2[j].size(); k++)
                temp[AR2[j][k]] = 0;
            if (temp[j] == 0)
                continue;
            for (int k = 0; k < N; k++)
            {
                if (temp[k] && k != j && k != i)
                {
                    centre = i;
                    leaf = j;
                }
            }
        }
    }

    if (centre == -1)
    {
        int N2 = N;
        if (N % 2 == 0)
            N2++;
        vector<int> perm(N2), C(N2);
        for (int i = 0; i < N2; i++)
        {
            perm[i] = i;
            if (i <= N2 / 2)
            {
                C[i] = i;
                C[N2 - i - 1] = i;
            }
        }
        cout << 2 * N2 << endl;
        for (int i = 0; i < N2; i++)
        {
            for (int k = 0; k < 2; k++)
            {
                for (int j = 0; j < N; j++)
                {
                    cout << C[perm[j]] << ' ';
                }
                cout << '\n';
            }
            swap(perm[0], perm[N2 - 1]);
            for (int j = 1; j < N2 - 1; j++)
                swap(perm[j], perm[j - 1]);
        }
        return 0;
    }
    UF.merge(centre, leaf);
    AR[centre].push_back(leaf);
    AR[leaf].push_back(centre);
    for (int j = 0; j < AR2[leaf].size(); j++)
        banned[AR2[leaf][j]] = 1;
    for (int i = 0; i < AR2[centre].size(); i++)
    {
        if (AR2[centre][i] == leaf)
            continue;
        if (banned[AR2[centre][i]])
            continue;
        if (UF.merge(centre, AR2[centre][i]))
        {
            AR[centre].push_back(AR2[centre][i]);
            AR[AR2[centre][i]].push_back(centre);
            for (int j = 0; j < AR2[AR2[centre][i]].size(); j++)
                banned[AR2[AR2[centre][i]][j]] = 1;
        }
    }
    for (int i = 0; i < N; i++)
    {
        if (i == centre)
            continue;
        for (int j = 0; j < AR2[i].size(); j++)
        {
            if (AR2[i][j] == centre)
                continue;
            if (UF.merge(i, AR2[i][j]))
            {
                AR[i].push_back(AR2[i][j]);
                AR[AR2[i][j]].push_back(i);
            }
        }
    }
    vector<int> par(N), deb(N, 1000), sub(N);
    vector<vector<int>> ans(600, vector<int>(N));
    for (int i = 0; i < 600; i++)
        for (int j = 0; j < N; j++)
            ans[i][j] = j;
    for (int i = 0; i < 200; i++)
    {
        ans[i * 2][AR[centre][i % 2]] = centre;
    }
    for (int i = 0; i < AR[centre].size(); i++)
    {
        int pos = 0;
        dfs2(AR[centre][i], centre, AR, par, deb, sub, pos, 0, i);
    }
    for (int i = 0; i < N; i++)
    {
        if (i == centre)
            continue;
        if (deb[i] == 0)
        {
            for (int j = 1; j < 400; j += 2)
                ans[j][i] = centre;
            continue;
        }
        if (sub[i] == 0)
            deb[i] += deb[i] / 2;
        if (sub[i] == 1)
        {
            deb[i] += deb[i] / 2;
            deb[i] += 2;
        }
        for (int j = deb[i] + 1; j < 400; j += 2)
        {
            ans[j][i] = par[i];
            if (sub[i] <= 1)
                j += 2;
        }
    }
    int cur = 400, last = centre;
    dfs(centre, centre, AR, ans, cur, last);
    cout << 600 << endl;
    for (int i = 0; i < 600; i++)
    {
        for (int j = 0; j < N; j++)
        {
            cout << ans[i][j] << ' ';
        }
        cout << endl;
    }
}

Compilation message (stderr)

Main.cpp: In function 'void dfs(int, int, std::vector<std::vector<int> >&, std::vector<std::vector<int> >&, int&, int&)':
Main.cpp:33:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     for (int i = 0; i < AR[x].size(); i++)
      |                     ~~^~~~~~~~~~~~~~
Main.cpp: In function 'void dfs2(int, int, std::vector<std::vector<int> >&, std::vector<int>&, std::vector<int>&, std::vector<int>&, int&, int, int)':
Main.cpp:49:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |     for (int i = 0; i < AR[x].size(); i++)
      |                     ~~^~~~~~~~~~~~~~
Main.cpp: In function 'void dfs3(int, std::vector<int>&, std::vector<std::vector<int> >&, int&, int)':
Main.cpp:60:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |     for (int i = 0; i < AR[x].size(); i++)
      |                     ~~^~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:94:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |             for (int k = 0; k < AR2[i].size(); k++)
      |                             ~~^~~~~~~~~~~~~~~
Main.cpp:96:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   96 |             for (int k = 0; k < AR2[j].size(); k++)
      |                             ~~^~~~~~~~~~~~~~~
Main.cpp:146:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  146 |     for (int j = 0; j < AR2[leaf].size(); j++)
      |                     ~~^~~~~~~~~~~~~~~~~~
Main.cpp:148:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  148 |     for (int i = 0; i < AR2[centre].size(); i++)
      |                     ~~^~~~~~~~~~~~~~~~~~~~
Main.cpp:158:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  158 |             for (int j = 0; j < AR2[AR2[centre][i]].size(); j++)
      |                             ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:166:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  166 |         for (int j = 0; j < AR2[i].size(); j++)
      |                         ~~^~~~~~~~~~~~~~~
Main.cpp:186:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  186 |     for (int i = 0; i < AR[centre].size(); i++)
      |                     ~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 11 / 11
• Subtask 4: 0 / 36
• Subtask 5: 0 / 30