oj.uz

Submission #1041080

# Submission time Handle Problem Language Result Execution time Memory
1041080 2024-08-01T15:07:20 Z jer033 Parachute rings (IOI12_rings) C++17
37 / 100
 4000 ms 256416 KB 
#include <bits/stdc++.h>
using namespace std;

int N;
int curr_answer;
bool second_stage;

class LinkedIn{
public:
    vector<vector<int>> edges;
    vector<int> chains;
    //value encoded: other endpoint of chain (itself if 0 connections), or -1 if it has 2 connections
    vector<int> degree;
    int cycle_count;
    int cycle_size;
    bool three_exists;

    LinkedIn(int N_)
    {
        edges = vector<vector<int>> (N_);
        chains = vector<int> (N_);
        for (int i=0; i<N_; i++)
            chains[i] = i;
        degree = vector<int> (N_, 0);
        
        cycle_count = 0;
        cycle_size = 0;
        three_exists = 0;
    };

    int CreateLink(int A, int B, bool care_about_edge)
    {
        degree[A]++;
        degree[B]++;
        
        if ((chains[A]>=0) and (chains[B]>=0))
        {
            if ((chains[A]==B) and (chains[B]==A))
            {
                cycle_count++;
                cycle_count = min(cycle_count, 2);
                if (cycle_count == 1)
                {
                    vector<int> visited(N, 0);
                    visited[A] = 1;
                    int curr = A;
                    cycle_size = 1;
                    while (curr!=B)
                    {
                        int next_node;
                        for (int c: edges[curr])
                            if (visited[c]==0)
                                next_node = c;
                        visited[next_node] = 1;
                        curr = next_node;
                        cycle_size++;
                    }
                    //cout << "A cycle of size " << cycle_size << " has been formed\n";
                }
                chains[A] = -1;
                chains[B] = -1;
            }
            else
            {
                int newchainsA, newchainsB;
                int newchains2A, newchains2B;
                if (chains[A]==A)
                    newchainsA = chains[B];
                else
                {
                    newchains2A = chains[B];
                    newchainsA = -1;
                }
                if (chains[B]==B)
                    newchainsB = chains[A];
                else
                {
                    newchains2B = chains[A];
                    newchainsB = -1;
                }

                if (chains[A]==A)
                    chains[A] = newchainsA;
                else
                {
                    chains[chains[A]] = newchains2A;
                    chains[A] = newchainsA;
                }

                if (chains[B]==B)
                    chains[B] = newchainsB;
                else
                {
                    chains[chains[B]] = newchains2B;
                    chains[B] = newchainsB;
                }
            }
        }
        else{
            three_exists = 1;
        }

        if (care_about_edge)
        {
            edges[A].push_back(B);
            edges[B].push_back(A);
        }

        if (degree[A]>=3)
            three_exists = 1;
        if (degree[B]>=3)
            three_exists = 1;

        /*for (int i=0; i<N; i++)
            cout << chains[i] << ' ';
        cout << '\n';*/

        if (three_exists)
            return 3;
        else if (cycle_count > 0)
            return min(cycle_count, 2);
        return 0;
    };

    int answer()
    {
        if (cycle_count>=2)
            return 0;
        if (cycle_count==1)
            return cycle_size;
        return N;
    }

    int answer_2()
    {
        if (three_exists)
            return 0;
        if (cycle_count >= 1)
            return 0;
        return 1;
    }
};

int c1, c2, c3, c4;
LinkedIn sys_0(0);
LinkedIn sys_1(0);
LinkedIn sys_2(0);
LinkedIn sys_3(0);
LinkedIn sys_4(0);

void Init(int N_) {
    N = N_;
    curr_answer = N_;
    sys_0 = LinkedIn(N_);
    second_stage = 0;
}

void Link(int A, int B) {
    if (second_stage == 0)
    {
        int result = sys_0.CreateLink(A, B, 1);
        if (result != 3)
        {
            curr_answer = sys_0.answer();
        }
        else
        {
            second_stage = 1;
            vector<vector<int>> con = sys_0.edges;
            vector<int> deg = sys_0.degree;
            int center;
            if (deg[A] == 3)
                center = A;
            else
                center = B;
            c1 = center;
            c2 = con[center][0];
            c3 = con[center][1];
            c4 = con[center][2];
            sys_1 = LinkedIn(N);
            sys_2 = LinkedIn(N);
            sys_3 = LinkedIn(N);
            sys_4 = LinkedIn(N);
            //cout << c1 << c2 << c3 << c4 << '\n';
            for (int i=0; i<N; i++)
                for (int j: con[i])
                    if (i<j)
                    {
                        if ((i!=c1) and (j!=c1))
                            int x = sys_1.CreateLink(i, j, 0);
                        if ((i!=c2) and (j!=c2))
                            int x = sys_2.CreateLink(i, j, 0);
                        if ((i!=c3) and (j!=c3))
                            int x = sys_3.CreateLink(i, j, 0);
                        if ((i!=c4) and (j!=c4))
                            int x = sys_4.CreateLink(i, j, 0);
                    }
            curr_answer = sys_1.answer_2() + sys_2.answer_2() + sys_3.answer_2() + sys_4.answer_2();
        }
    }
    else
    {
        int i = A;
        int j = B;
        if ((i!=c1) and (j!=c1))
            int x = sys_1.CreateLink(i, j, 0);
        if ((i!=c2) and (j!=c2))
            int x = sys_2.CreateLink(i, j, 0);
        if ((i!=c3) and (j!=c3))
            int x = sys_3.CreateLink(i, j, 0);
        if ((i!=c4) and (j!=c4))
            int x = sys_4.CreateLink(i, j, 0);
                    
        curr_answer = sys_1.answer_2() + sys_2.answer_2() + sys_3.answer_2() + sys_4.answer_2();
    }
}

int CountCritical() {
    return curr_answer;
}

/*int main()
{
    Init(1'000'000);
    for (int i=0; i<50'000; i++)
    {
        Link(i, i+1);
    }
    Link(76892, 291238);
    Link(4, 100);
    cout << CountCritical() << '\n';
}*/

Compilation message

rings.cpp: In function 'void Link(int, int)':
rings.cpp:190:33: warning: unused variable 'x' [-Wunused-variable]
  190 |                             int x = sys_1.CreateLink(i, j, 0);
      |                                 ^
rings.cpp:192:33: warning: unused variable 'x' [-Wunused-variable]
  192 |                             int x = sys_2.CreateLink(i, j, 0);
      |                                 ^
rings.cpp:194:33: warning: unused variable 'x' [-Wunused-variable]
  194 |                             int x = sys_3.CreateLink(i, j, 0);
      |                                 ^
rings.cpp:196:33: warning: unused variable 'x' [-Wunused-variable]
  196 |                             int x = sys_4.CreateLink(i, j, 0);
      |                                 ^
rings.cpp:206:17: warning: unused variable 'x' [-Wunused-variable]
  206 |             int x = sys_1.CreateLink(i, j, 0);
      |                 ^
rings.cpp:208:17: warning: unused variable 'x' [-Wunused-variable]
  208 |             int x = sys_2.CreateLink(i, j, 0);
      |                 ^
rings.cpp:210:17: warning: unused variable 'x' [-Wunused-variable]
  210 |             int x = sys_3.CreateLink(i, j, 0);
      |                 ^
rings.cpp:212:17: warning: unused variable 'x' [-Wunused-variable]
  212 |             int x = sys_4.CreateLink(i, j, 0);
      |                 ^
rings.cpp: In member function 'int LinkedIn::CreateLink(int, int, bool)':
rings.cpp:94:39: warning: 'newchains2B' may be used uninitialized in this function [-Wmaybe-uninitialized]
   94 |                     chains[chains[B]] = newchains2B;
rings.cpp:54:42: warning: 'next_node' may be used uninitialized in this function [-Wmaybe-uninitialized]
   54 |                         visited[next_node] = 1;
      |                                          ^

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 2 ms 1372 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 127 ms 33024 KB Output is correct
2 Correct 399 ms 175444 KB Output is correct
3 Correct 364 ms 185436 KB Output is correct
4 Correct 471 ms 80120 KB Output is correct
5 Correct 446 ms 80364 KB Output is correct
6 Correct 538 ms 78568 KB Output is correct
7 Correct 354 ms 185632 KB Output is correct
8 Correct 539 ms 233808 KB Output is correct
9 Correct 642 ms 256416 KB Output is correct
10 Correct 311 ms 77652 KB Output is correct

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 2 ms 1372 KB Output is correct
11 Execution timed out 4051 ms 1372 KB Time limit exceeded
12 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 2 ms 1372 KB Output is correct
11 Execution timed out 4051 ms 1372 KB Time limit exceeded
12 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 1 ms 1372 KB Output is correct
3 Correct 1 ms 1372 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 1372 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 1372 KB Output is correct
10 Correct 2 ms 1372 KB Output is correct
11 Correct 127 ms 33024 KB Output is correct
12 Correct 399 ms 175444 KB Output is correct
13 Correct 364 ms 185436 KB Output is correct
14 Correct 471 ms 80120 KB Output is correct
15 Correct 446 ms 80364 KB Output is correct
16 Correct 538 ms 78568 KB Output is correct
17 Correct 354 ms 185632 KB Output is correct
18 Correct 539 ms 233808 KB Output is correct
19 Correct 642 ms 256416 KB Output is correct
20 Correct 311 ms 77652 KB Output is correct
21 Execution timed out 4051 ms 1372 KB Time limit exceeded
22 Halted 0 ms 0 KB -