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Submission #516097

# Submission time Handle Problem Language Result Execution time Memory
516097 2022-01-20T11:20:24 Z 600Mihnea Parachute rings (IOI12_rings) C++17
100 / 100
 1357 ms 118892 KB 
#include <bits/stdc++.h>

using namespace std;

class DsuClass {
private:
  int n;
  int skip;
  vector<int> t;
  vector<int> deg;
  bool ok;

  int getComponent(int a) {
    assert(0 <= a && a < n);
    if (t[a] == a) return a;
    return t[a] = getComponent(t[a]);
  }


public:

  DsuClass() = default;

  DsuClass(int n, int skip) :
    n(n),
    skip(skip),
    t(n),
    ok(true),
    deg(n, 0) {

    iota(t.begin(), t.end(), 0);
  };

  void unite(int a, int b) {
    assert(0 <= a && a < n);
    assert(0 <= b && b < n);
    if (a == skip || b == skip) return;
    deg[a]++;
    deg[b]++;
    ok &= (deg[a] <= 2);
    ok &= (deg[b] <= 2);
    ok &= (getComponent(a) != getComponent(b));
    t[getComponent(a)] = getComponent(b);
  }

  bool isOk() {
    return ok;
  }

};

const int N = (int) 1e6 + 7;
int n;
int maxDeg = 0;
int maxDegVertex = 0;
vector<int> g[N];
bool Started = false;
int cycles = 0;
int sizeOfCycle = -1;
int parrent[N];

int root(int a) {
  if (parrent[a] == a) return a;
  return parrent[a] = root(parrent[a]);
}

void Init(int __n__) {

  assert(!Started);
  Started = true;

  n = __n__;


  for (int i = 0; i < n; i++) parrent[i] = i;
}

bool vis[N];
bool act[N];
int cntActive;

void computeSizeOfCycle(int a, int theParrent = -1) {
  act[a] = true;
  vis[a] = true;
  cntActive++;

  for (auto &b : g[a]) {
    if (act[b] && b != theParrent) {
      assert(sizeOfCycle == -1);
      sizeOfCycle = cntActive;
    }
    if (vis[b]) {
      continue;
    }
    computeSizeOfCycle(b, a);
  }

  cntActive--;
  act[a] = false;
}

queue<pair<int, int>> edgesQueue;

void Link(int a, int b) {
  assert(0 <= a && a < n);
  assert(0 <= b && b < n);

  g[a].push_back(b);
  g[b].push_back(a);

  edgesQueue.push({a, b});

  bool onCycle = (root(a) == root(b));

  if (onCycle) {
    cycles++;
    if (cycles == 1) {
      /// super duper mega fresh new cycle
      sizeOfCycle = -1;
      computeSizeOfCycle(a);
      assert(sizeOfCycle != -1);
    }
  }


  parrent[root(a)] = root(b);

  if ((int) g[a].size() > maxDeg) {
    maxDeg = (int) g[a].size();
    maxDegVertex = a;
  }

  if ((int) g[b].size() > maxDeg) {
    maxDeg = (int) g[b].size();
    maxDegVertex = b;
  }

}

vector<DsuClass> potentials;


int CountCritical() {
  if (maxDeg <= 2) {
    if (cycles == 0) {
      return n;
    }
    if (cycles == 1) {
      return sizeOfCycle;
    }
    if (cycles >= 2) {
      return 0; /// independent cycles are bad for your health
    }
  } else {
    /// maxDeg >= 3
    if (maxDeg == 3) {
      if (potentials.empty()) {
        potentials.push_back(DsuClass(n, maxDegVertex));
        for (auto &a : g[maxDegVertex]) {
          potentials.push_back(DsuClass(n, a));
        }
      }

    } else {
      /// maxDeg >= 4
      if (potentials.empty()) {
        potentials.push_back(DsuClass(n, maxDegVertex));
      }
      if ((int) potentials.size() >= 2) potentials.resize(1);
    }
    while (!edgesQueue.empty()) {
      int a = edgesQueue.front().first, b = edgesQueue.front().second;
      edgesQueue.pop();
      for (auto &v : potentials) {
        v.unite(a, b);
      }
    }
    int solution = 0;
    for (auto &v : potentials) {
      solution += v.isOk();
    }
    return solution;
  }
  return -1;
}

Compilation message

rings.cpp: In constructor 'DsuClass::DsuClass(int, int)':
rings.cpp:11:8: warning: 'DsuClass::ok' will be initialized after [-Wreorder]
   11 |   bool ok;
      |        ^~
rings.cpp:10:15: warning:   'std::vector<int> DsuClass::deg' [-Wreorder]
   10 |   vector<int> deg;
      |               ^~~
rings.cpp:24:3: warning:   when initialized here [-Wreorder]
   24 |   DsuClass(int n, int skip) :
      |   ^~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23756 KB Output is correct
2 Correct 15 ms 24048 KB Output is correct
3 Correct 14 ms 24096 KB Output is correct
4 Correct 13 ms 23788 KB Output is correct
5 Correct 13 ms 24068 KB Output is correct
6 Correct 16 ms 24340 KB Output is correct
7 Correct 13 ms 24012 KB Output is correct
8 Correct 13 ms 23944 KB Output is correct
9 Correct 14 ms 24224 KB Output is correct
10 Correct 18 ms 24216 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 305 ms 46392 KB Output is correct
2 Correct 757 ms 64808 KB Output is correct
3 Correct 1004 ms 84796 KB Output is correct
4 Correct 878 ms 82356 KB Output is correct
5 Correct 876 ms 84016 KB Output is correct
6 Correct 981 ms 118892 KB Output is correct
7 Correct 971 ms 83784 KB Output is correct
8 Correct 1239 ms 106256 KB Output is correct
9 Correct 1357 ms 111932 KB Output is correct
10 Correct 566 ms 79980 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23756 KB Output is correct
2 Correct 15 ms 24048 KB Output is correct
3 Correct 14 ms 24096 KB Output is correct
4 Correct 13 ms 23788 KB Output is correct
5 Correct 13 ms 24068 KB Output is correct
6 Correct 16 ms 24340 KB Output is correct
7 Correct 13 ms 24012 KB Output is correct
8 Correct 13 ms 23944 KB Output is correct
9 Correct 14 ms 24224 KB Output is correct
10 Correct 18 ms 24216 KB Output is correct
11 Correct 15 ms 24140 KB Output is correct
12 Correct 18 ms 24780 KB Output is correct
13 Correct 19 ms 24524 KB Output is correct
14 Correct 17 ms 24140 KB Output is correct
15 Correct 15 ms 24232 KB Output is correct
16 Correct 16 ms 24392 KB Output is correct
17 Correct 17 ms 24524 KB Output is correct
18 Correct 17 ms 24780 KB Output is correct
19 Correct 16 ms 24388 KB Output is correct
20 Correct 18 ms 24504 KB Output is correct

Subtask #4
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23756 KB Output is correct
2 Correct 15 ms 24048 KB Output is correct
3 Correct 14 ms 24096 KB Output is correct
4 Correct 13 ms 23788 KB Output is correct
5 Correct 13 ms 24068 KB Output is correct
6 Correct 16 ms 24340 KB Output is correct
7 Correct 13 ms 24012 KB Output is correct
8 Correct 13 ms 23944 KB Output is correct
9 Correct 14 ms 24224 KB Output is correct
10 Correct 18 ms 24216 KB Output is correct
11 Correct 15 ms 24140 KB Output is correct
12 Correct 18 ms 24780 KB Output is correct
13 Correct 19 ms 24524 KB Output is correct
14 Correct 17 ms 24140 KB Output is correct
15 Correct 15 ms 24232 KB Output is correct
16 Correct 16 ms 24392 KB Output is correct
17 Correct 17 ms 24524 KB Output is correct
18 Correct 17 ms 24780 KB Output is correct
19 Correct 16 ms 24388 KB Output is correct
20 Correct 18 ms 24504 KB Output is correct
21 Correct 27 ms 25572 KB Output is correct
22 Correct 40 ms 26556 KB Output is correct
23 Correct 45 ms 27464 KB Output is correct
24 Correct 49 ms 27416 KB Output is correct
25 Correct 25 ms 27500 KB Output is correct
26 Correct 47 ms 28056 KB Output is correct
27 Correct 50 ms 28688 KB Output is correct
28 Correct 64 ms 30944 KB Output is correct
29 Correct 47 ms 28100 KB Output is correct
30 Correct 56 ms 30332 KB Output is correct

Subtask #5
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23756 KB Output is correct
2 Correct 15 ms 24048 KB Output is correct
3 Correct 14 ms 24096 KB Output is correct
4 Correct 13 ms 23788 KB Output is correct
5 Correct 13 ms 24068 KB Output is correct
6 Correct 16 ms 24340 KB Output is correct
7 Correct 13 ms 24012 KB Output is correct
8 Correct 13 ms 23944 KB Output is correct
9 Correct 14 ms 24224 KB Output is correct
10 Correct 18 ms 24216 KB Output is correct
11 Correct 305 ms 46392 KB Output is correct
12 Correct 757 ms 64808 KB Output is correct
13 Correct 1004 ms 84796 KB Output is correct
14 Correct 878 ms 82356 KB Output is correct
15 Correct 876 ms 84016 KB Output is correct
16 Correct 981 ms 118892 KB Output is correct
17 Correct 971 ms 83784 KB Output is correct
18 Correct 1239 ms 106256 KB Output is correct
19 Correct 1357 ms 111932 KB Output is correct
20 Correct 566 ms 79980 KB Output is correct
21 Correct 15 ms 24140 KB Output is correct
22 Correct 18 ms 24780 KB Output is correct
23 Correct 19 ms 24524 KB Output is correct
24 Correct 17 ms 24140 KB Output is correct
25 Correct 15 ms 24232 KB Output is correct
26 Correct 16 ms 24392 KB Output is correct
27 Correct 17 ms 24524 KB Output is correct
28 Correct 17 ms 24780 KB Output is correct
29 Correct 16 ms 24388 KB Output is correct
30 Correct 18 ms 24504 KB Output is correct
31 Correct 27 ms 25572 KB Output is correct
32 Correct 40 ms 26556 KB Output is correct
33 Correct 45 ms 27464 KB Output is correct
34 Correct 49 ms 27416 KB Output is correct
35 Correct 25 ms 27500 KB Output is correct
36 Correct 47 ms 28056 KB Output is correct
37 Correct 50 ms 28688 KB Output is correct
38 Correct 64 ms 30944 KB Output is correct
39 Correct 47 ms 28100 KB Output is correct
40 Correct 56 ms 30332 KB Output is correct
41 Correct 177 ms 39444 KB Output is correct
42 Correct 466 ms 76248 KB Output is correct
43 Correct 254 ms 56652 KB Output is correct
44 Correct 633 ms 76352 KB Output is correct
45 Correct 845 ms 73416 KB Output is correct
46 Correct 559 ms 72564 KB Output is correct
47 Correct 818 ms 97096 KB Output is correct
48 Correct 480 ms 60724 KB Output is correct
49 Correct 543 ms 69376 KB Output is correct
50 Correct 575 ms 69120 KB Output is correct
51 Correct 266 ms 51916 KB Output is correct
52 Correct 706 ms 84100 KB Output is correct
53 Correct 469 ms 61488 KB Output is correct
54 Correct 1163 ms 89384 KB Output is correct
55 Correct 903 ms 73968 KB Output is correct