oj.uz

Submission #254423

# Submission time Handle Problem Language Result Execution time Memory
254423 2020-07-30T00:59:48 Z sandoval Parachute rings (IOI12_rings) C++11
20 / 100
 4000 ms 173368 KB 
#include <bits/stdc++.h>

using namespace std;
using ii = pair<int,int>;
using ll = long long;

constexpr int MAXN = 5+1e6;

struct dsu {
private:
vector<int> f,sz;
public:
dsu() = default;
void reset(int n) {
  sz.assign(n, 1); f.resize(n);
  for (int i = 0; i < n; ++i) f[i] = i;
}
int find(int x) {return f[x] == x ? x : f[x] = find(f[x]);}
bool join(int x, int y) {
  if ((x = find(x)) == (y = find(y))) return false;
  if (sz[x] < sz[y]) swap(x,y);
  sz[x] += sz[y];
  f[y] = x;
  return true;
}};

namespace data {
vector<ii> history; // OK!
set<int> active; // OK!

int deg[MAXN]; // OK!
dsu* graphs[MAXN]; // OK!

set<int> byd[5]; // OK!
int phase; // OK!
dsu general; // OK!

int N; // OK!
vector<int> G[MAXN]; // OK!

bool visited[MAXN]; // OK!

bool okPhase2; // OK!
vector<int> endPointsPhase2; // OK!

int degPhase3[MAXN], rootPhase3;
bool okPhase3;

int* degPhase4[MAXN];
bool initPhase4[MAXN]; // OK!
bool okPhase4[MAXN];


void keep_only(const set<int>& keep) {
  for (set<int>::iterator it = active.begin(), nx; it != active.end(); it = nx) {
    nx = next(it);
    if (keep.find(*it) == keep.end()) {
      active.erase(it);
    }
  }
}

void initializePhase3(int u) {
  // assert(graphs[u] == nullptr);
  okPhase3 = true;
  rootPhase3 = u;
  for (int i = 0; i < N; ++i) {
    degPhase3[i] = 0;
  }

  graphs[u] = new dsu();
  graphs[u]->reset(N);
  for (auto x : history) {
    if (x.first == u || x.second == u) continue;
    okPhase3 &= (++degPhase3[x.first] <= 2);
    okPhase3 &= (++degPhase3[x.second] <= 2);
    okPhase3 &= (graphs[rootPhase3]->join(x.first, x.second));
  }

  if (!okPhase3) {
    keep_only({});
  }
}
void initPhase4PerNode(int u) {
  assert(!initPhase4[u]);
  assert(degPhase4[u] == nullptr);

  initPhase4[u] = true;
  okPhase4[u] = true;
  graphs[u] = new dsu(); graphs[u]->reset(N);
  degPhase4[u] = new int[N];
  for (int i = 0; i < N; ++i) degPhase4[u][i] = 0;

  for (auto x : history) {
    if (x.first == u || x.second == u) continue;
    okPhase4[u] &= (++degPhase4[u][x.first] <= 2);
    okPhase4[u] &= (++degPhase4[u][x.second] <= 2);
    okPhase4[u] &= (graphs[u]->join(x.first, x.second));
  }
}
void restart_visit() {
  fill(visited, visited+N, false);
}
void reset(int n) {
  N=n;
  history.clear();
  active.clear();

  for (int i = 0; i < 5; ++i) byd[i].clear();
  for (int i = 0; i < n; ++i) {
    deg[i] = 0;
    G[i].clear();
    if (graphs[i] != nullptr) {
      delete graphs[i];
      graphs[i] = nullptr;
    }
    if (degPhase4[i] != nullptr) {
      delete degPhase4[i];
      degPhase4[i] = nullptr;
    }

    active.insert(i);
    byd[0].insert(i);
    initPhase4[i] = false;
  }
  phase = 1;
  general.reset(n);
  okPhase2 = true;
  endPointsPhase2.clear();
}}

void Init(int N) {
  data::reset(N);
}

bool dfs(int A, int B, set<int>& path) {
  data::visited[A] = true;
  if (A == B) {
    path.insert(A);
    return true;
  }

  for (int v : data::G[A]) {
    if (!data::visited[v] && dfs(v, B, path)) {
      path.insert(A);
      return true;
    }
  }
  return false;
}

void Link(int A, int B) {
  data::history.push_back({A,B});

  using namespace data;
  if (active.empty()) return;

  byd[deg[A]].erase(A);
  byd[deg[B]].erase(B);

  deg[A] = min(1+deg[A], 4);
  deg[B] = min(1+deg[B], 4);

  byd[deg[A]].insert(A);
  byd[deg[B]].insert(B);

  int largest = -1;
  for (int i = 4; i >= 0; --i) {
    if ((int)byd[i].size() >= 1) {
      largest = i;
      break;
    }
  }

  assert(largest != -1);
  if (phase == 1) {
    assert(largest >= 0 && largest <= 2);
    if (largest == 2) phase = 2;
  } else if (phase == 2) {
    assert(largest >= 2);
    if (largest == 3) phase = 4;
  } else if (phase == 4) {
    assert(largest >= 3);
    if (largest == 4) phase = 5;
  }

  if (phase == 1) {
    general.join(A,B);
    G[A].push_back(B);
    G[B].push_back(A);
  } else if (phase == 2) {
    bool f = general.join(A,B);
    if (!f) {
      if (okPhase2) {
        set<int> path;
        restart_visit();
        dfs(A,B,path);
        keep_only(path);
        okPhase2 = false;
        endPointsPhase2.push_back(A);
        endPointsPhase2.push_back(B);
      } else {
        auto it = find(endPointsPhase2.begin(), endPointsPhase2.end(), A);
        auto it2 = find(endPointsPhase2.begin(), endPointsPhase2.end(), B);
        vector<int>::iterator de = endPointsPhase2.end();

        if (it != endPointsPhase2.end()) {
          de = it;
          endPointsPhase2.erase(it2);
        } else if (it2 != endPointsPhase2.end()) {
          de = it2;
          endPointsPhase2.erase(it);
        } else {
          keep_only({});
          endPointsPhase2.clear();
        }

        if (de != endPointsPhase2.end()) {
          keep_only({*de});
          initializePhase3(*de);
          phase = 3;
        }
      }
    }

    G[A].push_back(B);
    G[B].push_back(A);
  } else if (phase == 3) {
    if (A == rootPhase3 || B == rootPhase3) return;
    okPhase3 &= graphs[rootPhase3]->join(A,B);
    okPhase3 &= (++degPhase3[A] <= 2);
    okPhase3 &= (++degPhase3[B] <= 2);
    if (!okPhase3) keep_only({});
  } else if (phase == 4) {
    G[A].push_back(B);
    G[B].push_back(A);
    const int sz = (int)byd[3].size();
    assert(sz>0);
    int fNode = *byd[3].begin();
    set<int> check;

    if (sz >= 5) {
      keep_only({});
    } else if (sz >= 1 && sz <= 4) {
      for (auto x : G[fNode]) {
        bool ok = true;
        for (auto u : byd[3]) {
          if (find(G[u].begin(), G[u].end(), x) == G[u].end()) {
            ok = false;
            break;
          }
        }

        if (ok) {
          check.insert(x);
        }
      }
      for (auto u : byd[3]) check.insert(u);
    } else {
      // assert(false);
    }

    keep_only(check);
    set<int> keep;

    for (auto x : active) {
      if (!initPhase4[x]) {
        initPhase4PerNode(x);
      } else {
        if (A != x && B != x) {
          okPhase4[x] &= (++degPhase4[x][A] <= 2);
          okPhase4[x] &= (++degPhase4[x][B] <= 2);
          okPhase4[x] &= (graphs[x]->join(A,B));
        }
      }

      if (okPhase4[x]) {
        keep.insert(x);
      }
    }

    keep_only(keep);
  } else if (phase == 5) {
    assert(!byd[4].empty());
    if ((int)byd[4].size() == 1) {
      keep_only({*byd[4].begin()});
      initializePhase3(*byd[4].begin());
      phase = 3;
    } else if ((int)byd[4].size() >= 2) {
      keep_only({});
    }
  }
}

int CountCritical() {
  return (int)data::active.size();
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 25 ms 24832 KB Output is correct
4 Correct 15 ms 23936 KB Output is correct
5 Correct 19 ms 24448 KB Output is correct
6 Correct 24 ms 25088 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 20 ms 24576 KB Output is correct
9 Correct 26 ms 24832 KB Output is correct
10 Correct 25 ms 24832 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 3645 ms 99816 KB Output is correct
2 Execution timed out 4107 ms 173368 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 25 ms 24832 KB Output is correct
4 Correct 15 ms 23936 KB Output is correct
5 Correct 19 ms 24448 KB Output is correct
6 Correct 24 ms 25088 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 20 ms 24576 KB Output is correct
9 Correct 26 ms 24832 KB Output is correct
10 Correct 25 ms 24832 KB Output is correct
11 Correct 25 ms 24832 KB Output is correct
12 Correct 36 ms 25728 KB Output is correct
13 Correct 34 ms 25848 KB Output is correct
14 Correct 29 ms 25728 KB Output is correct
15 Correct 33 ms 27384 KB Output is correct
16 Runtime error 65 ms 51320 KB Execution killed with signal 11 (could be triggered by violating memory limits)
17 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 25 ms 24832 KB Output is correct
4 Correct 15 ms 23936 KB Output is correct
5 Correct 19 ms 24448 KB Output is correct
6 Correct 24 ms 25088 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 20 ms 24576 KB Output is correct
9 Correct 26 ms 24832 KB Output is correct
10 Correct 25 ms 24832 KB Output is correct
11 Correct 25 ms 24832 KB Output is correct
12 Correct 36 ms 25728 KB Output is correct
13 Correct 34 ms 25848 KB Output is correct
14 Correct 29 ms 25728 KB Output is correct
15 Correct 33 ms 27384 KB Output is correct
16 Runtime error 65 ms 51320 KB Execution killed with signal 11 (could be triggered by violating memory limits)
17 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 25 ms 24832 KB Output is correct
4 Correct 15 ms 23936 KB Output is correct
5 Correct 19 ms 24448 KB Output is correct
6 Correct 24 ms 25088 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 20 ms 24576 KB Output is correct
9 Correct 26 ms 24832 KB Output is correct
10 Correct 25 ms 24832 KB Output is correct
11 Correct 3645 ms 99816 KB Output is correct
12 Execution timed out 4107 ms 173368 KB Time limit exceeded
13 Halted 0 ms 0 KB -