oj.uz

Submission #254430

# Submission time Handle Problem Language Result Execution time Memory
254430 2020-07-30T01:30:23 Z sandoval Parachute rings (IOI12_rings) C++11
52 / 100
 4000 ms 174252 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);
        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 22 ms 24704 KB Output is correct
3 Correct 22 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 22 ms 24960 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 18 ms 24448 KB Output is correct
9 Correct 25 ms 24832 KB Output is correct
10 Correct 26 ms 24832 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2771 ms 99896 KB Output is correct
2 Execution timed out 4094 ms 174252 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 22 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 22 ms 24960 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 18 ms 24448 KB Output is correct
9 Correct 25 ms 24832 KB Output is correct
10 Correct 26 ms 24832 KB Output is correct
11 Correct 23 ms 24952 KB Output is correct
12 Correct 31 ms 25720 KB Output is correct
13 Correct 33 ms 25852 KB Output is correct
14 Correct 25 ms 25728 KB Output is correct
15 Correct 32 ms 27392 KB Output is correct
16 Correct 29 ms 25344 KB Output is correct
17 Correct 21 ms 25600 KB Output is correct
18 Correct 27 ms 27264 KB Output is correct
19 Correct 32 ms 25464 KB Output is correct
20 Correct 35 ms 25856 KB Output is correct

Subtask #4
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 22 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 22 ms 24960 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 18 ms 24448 KB Output is correct
9 Correct 25 ms 24832 KB Output is correct
10 Correct 26 ms 24832 KB Output is correct
11 Correct 23 ms 24952 KB Output is correct
12 Correct 31 ms 25720 KB Output is correct
13 Correct 33 ms 25852 KB Output is correct
14 Correct 25 ms 25728 KB Output is correct
15 Correct 32 ms 27392 KB Output is correct
16 Correct 29 ms 25344 KB Output is correct
17 Correct 21 ms 25600 KB Output is correct
18 Correct 27 ms 27264 KB Output is correct
19 Correct 32 ms 25464 KB Output is correct
20 Correct 35 ms 25856 KB Output is correct
21 Correct 93 ms 30472 KB Output is correct
22 Correct 158 ms 34340 KB Output is correct
23 Correct 223 ms 37000 KB Output is correct
24 Correct 213 ms 39928 KB Output is correct
25 Correct 93 ms 40584 KB Output is correct
26 Correct 210 ms 40408 KB Output is correct
27 Correct 259 ms 36080 KB Output is correct
28 Correct 93 ms 37872 KB Output is correct
29 Correct 99 ms 39960 KB Output is correct
30 Correct 438 ms 39664 KB Output is correct

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23808 KB Output is correct
2 Correct 22 ms 24704 KB Output is correct
3 Correct 22 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 22 ms 24960 KB Output is correct
7 Correct 16 ms 24704 KB Output is correct
8 Correct 18 ms 24448 KB Output is correct
9 Correct 25 ms 24832 KB Output is correct
10 Correct 26 ms 24832 KB Output is correct
11 Correct 2771 ms 99896 KB Output is correct
12 Execution timed out 4094 ms 174252 KB Time limit exceeded
13 Halted 0 ms 0 KB -