oj.uz

Submission #836418

# Submission time Handle Problem Language Result Execution time Memory
836418 2023-08-24T11:02:16 Z SamAnd Thousands Islands (IOI22_islands) C++17
55 / 100
 38 ms 6136 KB 
#include "islands.h"
#include <variant>
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
typedef long long ll;
const int N = 1003, M = 200005;

vector<pair<int, int> > g[N];
vector<int> ans;

int c[N];
int pi[N];
int p[N];
bool dfs(int x)
{
    c[x] = 1;
    for (int i = 0; i < g[x].size(); ++i)
    {
        int h = g[x][i].fi;
        int hi = g[x][i].se;
        if (c[h] == 1)
        {
            vector<int> s;
            int y = h;
            while (y)
            {
                s.push_back(pi[y]);
                y = p[y];
            }
            reverse(all(s));

            vector<int> v;
            y = x;
            while (y != h)
            {
                v.push_back(pi[y]);
                y = p[y];
            }
            reverse(all(v));
            v.push_back(hi);

            for (int i = 0; i < sz(s); ++i)
                ans.push_back(s[i]);
            for (int i = 0; i < sz(v); ++i)
                ans.push_back(v[i]);
            for (int i = 0; i < sz(v); ++i)
                ans.push_back((v[i] ^ 1));
            for (int i = sz(v) - 1; i >= 0; --i)
                ans.push_back(v[i]);
            for (int i = sz(v) - 1; i >= 0; --i)
                ans.push_back((v[i] ^ 1));
            for (int i = sz(s) - 1; i >= 0; --i)
                ans.push_back(s[i]);
            return true;
        }
        else if (!c[h])
        {
            p[h] = x;
            pi[h] = hi;
            if (dfs(h))
                return true;
        }
    }
    c[x] = 2;
    return false;
}

std::variant<bool, std::vector<int> > find_journey(int N, int M, std::vector<int> U, std::vector<int> V)
{
    for (int i = 0; i < M; ++i)
    {
        g[U[i]].push_back(m_p(V[i], i));
    }
    if (N == 2)
    {
        if (sz(g[0]) >= 2 && sz(g[1]) >= 1)
        {
            ans.push_back(g[0][0].se);
            ans.push_back(g[1][0].se);
            ans.push_back(g[0][1].se);
            ans.push_back(g[0][0].se);
            ans.push_back(g[1][0].se);
            ans.push_back(g[0][1].se);
            return ans;
        }
        return false;
    }

    bool z = true;
    if (M % 2 == 1)
    {
        z = false;
    }
    else
    {
        for (int i = 0; i < M; i += 2)
        {
            if (m_p(U[i], V[i]) != m_p(V[i + 1], U[i + 1]))
            {
                z = false;
                break;
            }
        }
    }

    if (z)
    {
        int x = 0;
        while (1)
        {
            vector<pair<int, int> > v;
            for (int i = 0; i < g[x].size(); ++i)
            {
                int h = g[x][i].fi;
                int hi = g[x][i].se;
                if (!ans.empty() && ans.back() / 2 == hi / 2)
                    continue;
                v.push_back(m_p(h, hi));
            }
            if (v.empty())
                return false;
            if (sz(v) == 1)
            {
                ans.push_back(v[0].se);
                x = v[0].fi;
                continue;
            }
            vector<int> yans = ans;
            ans.push_back(v[0].se);
            ans.push_back((v[0].se ^ 1));
            ans.push_back(v[1].se);
            ans.push_back((v[1].se ^ 1));
            ans.push_back((v[0].se ^ 1));
            ans.push_back(v[0].se);
            ans.push_back((v[1].se ^ 1));
            ans.push_back(v[1].se);
            for (int i = sz(yans) - 1; i >= 0; --i)
                ans.push_back(yans[i]);
            return ans;
        }
        assert(false);
    }

    z = true;
    if (M % 2 == 1)
    {
        z = false;
    }
    else
    {
        for (int i = 0; i < M; i += 2)
        {
            if (m_p(U[i], V[i]) != m_p(U[i + 1], V[i + 1]))
            {
                z = false;
                break;
            }
        }
    }

    if (z)
    {
        if (!dfs(0))
            return false;
        return ans;
    }
    else
    {
        int k0, k1, k2, k3;
        for (int i = 0; i < g[0].size(); ++i)
        {
            int h = g[0][i].fi;
            int hi = g[0][i].se;
            if (h == 1)
            {
                k0 = hi;
            }
            if (h == 2)
            {
                k1 = hi;
            }
        }
        for (int i = 0; i < g[1].size(); ++i)
        {
            int h = g[1][i].fi;
            int hi = g[1][i].se;
            if (h == 0)
            {
                k2 = hi;
            }
        }
        for (int i = 0; i < g[2].size(); ++i)
        {
            int h = g[2][i].fi;
            int hi = g[2][i].se;
            if (h == 0)
            {
                k3 = hi;
            }
        }
        ans.push_back(k0);
        ans.push_back(k2);
        ans.push_back(k1);
        ans.push_back(k3);
        ans.push_back(k2);
        ans.push_back(k0);
        ans.push_back(k3);
        ans.push_back(k1);
        return ans;
    }
}

/*int main()
{
    int n, m;
    cin >> n >> m;
    vector<int> u, v;
    for (int i = 0; i < m; ++i)
    {
        int x, y;
        cin >> x >> y;
        u.push_back(x);
        v.push_back(y);
    }
    cout << find_journey(n, m, u, v) << "\n";
    return 0;
}*/

/*
5 6
0 1
1 0
1 3
3 1
0 4
4 0

3 6
0 1
1 0
1 2
2 1
2 0
0 2
*/

Compilation message

islands.cpp: In function 'bool dfs(int)':
islands.cpp:22:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     for (int i = 0; i < g[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~
islands.cpp: In function 'std::variant<bool, std::vector<int, std::allocator<int> > > find_journey(int, int, std::vector<int>, std::vector<int>)':
islands.cpp:117:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |             for (int i = 0; i < g[x].size(); ++i)
      |                             ~~^~~~~~~~~~~~~
islands.cpp:175:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  175 |         for (int i = 0; i < g[0].size(); ++i)
      |                         ~~^~~~~~~~~~~~~
islands.cpp:188:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  188 |         for (int i = 0; i < g[1].size(); ++i)
      |                         ~~^~~~~~~~~~~~~
islands.cpp:197:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  197 |         for (int i = 0; i < g[2].size(); ++i)
      |                         ~~^~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 232 KB Output is correct
5 Correct 1 ms 248 KB Output is correct
6 Correct 0 ms 256 KB Output is correct
7 Correct 27 ms 5224 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 256 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 22 ms 4656 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 14 ms 3040 KB Output is correct
18 Correct 17 ms 2636 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 1 ms 212 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 25 ms 4656 KB Output is correct

Subtask #4
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 24 ms 5096 KB Output is correct
4 Correct 29 ms 5200 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 2 ms 468 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 2 ms 468 KB Output is correct
13 Correct 2 ms 596 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 2 ms 504 KB Output is correct
16 Correct 1 ms 388 KB Output is correct
17 Correct 0 ms 384 KB Output is correct
18 Correct 1 ms 384 KB Output is correct
19 Correct 1 ms 384 KB Output is correct
20 Correct 31 ms 5764 KB Output is correct
21 Correct 25 ms 5148 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 2 ms 596 KB Output is correct
27 Correct 31 ms 5700 KB Output is correct
28 Correct 30 ms 5796 KB Output is correct
29 Correct 1 ms 376 KB Output is correct
30 Correct 38 ms 6136 KB Output is correct
31 Correct 0 ms 340 KB Output is correct
32 Correct 29 ms 5708 KB Output is correct
33 Correct 25 ms 5272 KB Output is correct
34 Correct 14 ms 3036 KB Output is correct
35 Correct 1 ms 340 KB Output is correct
36 Correct 25 ms 4788 KB Output is correct
37 Correct 26 ms 5788 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 23 ms 4872 KB Output is correct
40 Correct 1 ms 340 KB Output is correct
41 Correct 29 ms 6108 KB Output is correct
42 Correct 27 ms 5784 KB Output is correct
43 Correct 1 ms 340 KB Output is correct
44 Correct 1 ms 340 KB Output is correct
45 Correct 2 ms 596 KB Output is correct
46 Correct 11 ms 2632 KB Output is correct

Subtask #5
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 232 KB Output is correct
5 Correct 1 ms 248 KB Output is correct
6 Correct 0 ms 256 KB Output is correct
7 Correct 27 ms 5224 KB Output is correct
8 Correct 0 ms 256 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 22 ms 4656 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 212 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 0 ms 212 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 212 KB Output is correct
27 Correct 0 ms 212 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 14 ms 3040 KB Output is correct
31 Correct 17 ms 2636 KB Output is correct
32 Correct 0 ms 212 KB Output is correct
33 Correct 0 ms 212 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 0 ms 212 KB Output is correct
36 Correct 25 ms 4656 KB Output is correct
37 Partially correct 1 ms 212 KB Output is partially correct
38 Correct 1 ms 256 KB Output is correct
39 Incorrect 1 ms 212 KB Output isn't correct
40 Halted 0 ms 0 KB -