oj.uz

Submission #254435

# Submission time Handle Problem Language Result Execution time Memory
254435 2020-07-30T01:49:07 Z sandoval Parachute rings (IOI12_rings) C++11
20 / 100
 4000 ms 178760 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) {
  active = keep;
}

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;

  if (deg[A] < 4) {
    byd[deg[A]].erase(A);
    deg[A]++;
    byd[deg[A]].insert(A);
  }

  if (deg[B] < 4) {
    byd[deg[B]].erase(B);
    deg[B]++;
    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);
        int u = -1;

        if (it != endPointsPhase2.end()) {
          u = *it;
        } else if (it2 != endPointsPhase2.end()) {
          u = *it2;
        } else {
          keep_only({});
        }

        endPointsPhase2.clear();

        if (u != -1) {
          keep_only({u});
          initializePhase3(u);
          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 13 ms 23808 KB Output is correct
2 Correct 21 ms 24704 KB Output is correct
3 Correct 21 ms 24832 KB Output is correct
4 Correct 14 ms 23936 KB Output is correct
5 Correct 18 ms 24448 KB Output is correct
6 Correct 25 ms 24952 KB Output is correct
7 Correct 16 ms 24832 KB Output is correct
8 Correct 19 ms 24448 KB Output is correct
9 Correct 23 ms 24832 KB Output is correct
10 Correct 24 ms 24952 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2485 ms 99960 KB Output is correct
2 Execution timed out 4086 ms 178760 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23808 KB Output is correct
2 Correct 21 ms 24704 KB Output is correct
3 Correct 21 ms 24832 KB Output is correct
4 Correct 14 ms 23936 KB Output is correct
5 Correct 18 ms 24448 KB Output is correct
6 Correct 25 ms 24952 KB Output is correct
7 Correct 16 ms 24832 KB Output is correct
8 Correct 19 ms 24448 KB Output is correct
9 Correct 23 ms 24832 KB Output is correct
10 Correct 24 ms 24952 KB Output is correct
11 Correct 22 ms 24832 KB Output is correct
12 Correct 32 ms 26240 KB Output is correct
13 Incorrect 33 ms 25848 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23808 KB Output is correct
2 Correct 21 ms 24704 KB Output is correct
3 Correct 21 ms 24832 KB Output is correct
4 Correct 14 ms 23936 KB Output is correct
5 Correct 18 ms 24448 KB Output is correct
6 Correct 25 ms 24952 KB Output is correct
7 Correct 16 ms 24832 KB Output is correct
8 Correct 19 ms 24448 KB Output is correct
9 Correct 23 ms 24832 KB Output is correct
10 Correct 24 ms 24952 KB Output is correct
11 Correct 22 ms 24832 KB Output is correct
12 Correct 32 ms 26240 KB Output is correct
13 Incorrect 33 ms 25848 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23808 KB Output is correct
2 Correct 21 ms 24704 KB Output is correct
3 Correct 21 ms 24832 KB Output is correct
4 Correct 14 ms 23936 KB Output is correct
5 Correct 18 ms 24448 KB Output is correct
6 Correct 25 ms 24952 KB Output is correct
7 Correct 16 ms 24832 KB Output is correct
8 Correct 19 ms 24448 KB Output is correct
9 Correct 23 ms 24832 KB Output is correct
10 Correct 24 ms 24952 KB Output is correct
11 Correct 2485 ms 99960 KB Output is correct
12 Execution timed out 4086 ms 178760 KB Time limit exceeded
13 Halted 0 ms 0 KB -