oj.uz

Submission #254441

# Submission time Handle Problem Language Result Execution time Memory
254441 2020-07-30T02:03:48 Z sandoval Parachute rings (IOI12_rings) C++11
52 / 100
 4000 ms 242668 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;

vector<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;
  fill(degPhase3, degPhase3+N, 0);

  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].reset(N);
  degPhase4[u].assign(N,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();
    degPhase4[i].clear();

    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 55 ms 94328 KB Output is correct
2 Correct 65 ms 95096 KB Output is correct
3 Correct 65 ms 95224 KB Output is correct
4 Correct 63 ms 94456 KB Output is correct
5 Correct 59 ms 94840 KB Output is correct
6 Correct 63 ms 95480 KB Output is correct
7 Correct 64 ms 95100 KB Output is correct
8 Correct 60 ms 94968 KB Output is correct
9 Correct 66 ms 95224 KB Output is correct
10 Correct 64 ms 95228 KB Output is correct

Subtask #2
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2908 ms 170248 KB Output is correct
2 Execution timed out 4086 ms 242668 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 94328 KB Output is correct
2 Correct 65 ms 95096 KB Output is correct
3 Correct 65 ms 95224 KB Output is correct
4 Correct 63 ms 94456 KB Output is correct
5 Correct 59 ms 94840 KB Output is correct
6 Correct 63 ms 95480 KB Output is correct
7 Correct 64 ms 95100 KB Output is correct
8 Correct 60 ms 94968 KB Output is correct
9 Correct 66 ms 95224 KB Output is correct
10 Correct 64 ms 95228 KB Output is correct
11 Correct 67 ms 95224 KB Output is correct
12 Correct 73 ms 96168 KB Output is correct
13 Correct 85 ms 96248 KB Output is correct
14 Correct 77 ms 95992 KB Output is correct
15 Correct 82 ms 97656 KB Output is correct
16 Correct 71 ms 95864 KB Output is correct
17 Correct 62 ms 95992 KB Output is correct
18 Correct 70 ms 97656 KB Output is correct
19 Correct 72 ms 95864 KB Output is correct
20 Correct 85 ms 96248 KB Output is correct

Subtask #4
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 94328 KB Output is correct
2 Correct 65 ms 95096 KB Output is correct
3 Correct 65 ms 95224 KB Output is correct
4 Correct 63 ms 94456 KB Output is correct
5 Correct 59 ms 94840 KB Output is correct
6 Correct 63 ms 95480 KB Output is correct
7 Correct 64 ms 95100 KB Output is correct
8 Correct 60 ms 94968 KB Output is correct
9 Correct 66 ms 95224 KB Output is correct
10 Correct 64 ms 95228 KB Output is correct
11 Correct 67 ms 95224 KB Output is correct
12 Correct 73 ms 96168 KB Output is correct
13 Correct 85 ms 96248 KB Output is correct
14 Correct 77 ms 95992 KB Output is correct
15 Correct 82 ms 97656 KB Output is correct
16 Correct 71 ms 95864 KB Output is correct
17 Correct 62 ms 95992 KB Output is correct
18 Correct 70 ms 97656 KB Output is correct
19 Correct 72 ms 95864 KB Output is correct
20 Correct 85 ms 96248 KB Output is correct
21 Correct 141 ms 101112 KB Output is correct
22 Correct 220 ms 104816 KB Output is correct
23 Correct 251 ms 107504 KB Output is correct
24 Correct 263 ms 109688 KB Output is correct
25 Correct 144 ms 110200 KB Output is correct
26 Correct 232 ms 110068 KB Output is correct
27 Correct 318 ms 106480 KB Output is correct
28 Correct 136 ms 108272 KB Output is correct
29 Correct 144 ms 110360 KB Output is correct
30 Correct 466 ms 110188 KB Output is correct

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 94328 KB Output is correct
2 Correct 65 ms 95096 KB Output is correct
3 Correct 65 ms 95224 KB Output is correct
4 Correct 63 ms 94456 KB Output is correct
5 Correct 59 ms 94840 KB Output is correct
6 Correct 63 ms 95480 KB Output is correct
7 Correct 64 ms 95100 KB Output is correct
8 Correct 60 ms 94968 KB Output is correct
9 Correct 66 ms 95224 KB Output is correct
10 Correct 64 ms 95228 KB Output is correct
11 Correct 2908 ms 170248 KB Output is correct
12 Execution timed out 4086 ms 242668 KB Time limit exceeded
13 Halted 0 ms 0 KB -