Submission #465826

# Submission time Handle Problem Language Result Execution time Memory
465826 2021-08-16T19:31:01 Z alexxela12345 Fountain Parks (IOI21_parks) C++17
5 / 100
3090 ms 120600 KB
#include "parks.h"
#include <bits/stdc++.h>

using namespace std;

mt19937 rd(179);

int randint(int l, int r) {
  int b = r - l + 1;
  int a = rd() % b + b;
  a %= b;
  return a + l;
}

vector<int> pa, ra;

int get(int v) {
  if (pa[v] == v)
    return v;
  return pa[v] = get(pa[v]);
}
void merge(int a, int b) {
  a = get(a);
  b = get(b);
  assert(a != b);
  if (ra[b] > ra[a])
    swap(a, b);
  pa[b] = a;
  if (ra[a] == ra[b])
    ra[a]++;
}

vector<vector<int>> g;
vector<int> used;

void dfs(int v) {
  used[v] = 1;
  deque<int> q;
  q.push_back(v);
  while (!q.empty()) {
    int v = q.front();
    q.pop_front();
    for (int u : g[v]) {
      if (!used[u]) {
        used[u] = 1;
        q.push_back(u);
      }
    }
  }
}

int construct_roads(std::vector<int> x, std::vector<int> y) {
  if (x.size() == 1) {
    build({}, {}, {}, {});
    return 1;
  }
  map<pair<int, int>, int> byc;
  int n = x.size();
  for (int i = 0; i < n; i++) {
    byc[{x[i], y[i]}] = i;
  }
  g.clear();
  g.resize(n);
  map<pair<int, int>, int> cnt;
  pa.assign(n, 0);
  ra.assign(n, 0);
  iota(pa.begin(), pa.end(), 0);
  set<pair<int, int>> alive;

  auto add = [&](int i, int j) {
    if (i < j) {
      alive.insert({i, j});
      g[i].push_back(j);
      g[j].push_back(i);
      if (x[i] == x[j]) {
        cnt[{x[i] + 1, (y[i] + y[j]) / 2}] += 1;
        cnt[{x[i] - 1, (y[i] + y[j]) / 2}] += 1;
      } else {
        cnt[{(x[i] + x[j]) / 2, y[i] + 1}] += 1;
        cnt[{(x[i] + x[j]) / 2, y[i] - 1}] += 1;
      }
    }
  };
  for (int i = 0; i < n; i++) {
    {
      pair<int, int> pp = {x[i], y[i]};
      pp.first += 2;
      if (byc.count(pp)) {
        add(i, byc[pp]);
      }
    }
    {
      pair<int, int> pp = {x[i], y[i]};
      pp.second += 2;
      if (byc.count(pp)) {
        add(i, byc[pp]);
      }
    }
    {
      pair<int, int> pp = {x[i], y[i]};
      pp.first -= 2;
      if (byc.count(pp)) {
        add(i, byc[pp]);
      }
    }
    {
      pair<int, int> pp = {x[i], y[i]};
      pp.second -= 2;
      if (byc.count(pp)) {
        add(i, byc[pp]);
      }
    }
  }
  used.assign(n, 0);
  dfs(0);
  if (*min_element(used.begin(), used.end()) == 0) {
    return 0;
  }
  set<pair<int, int>> ones;
  for (auto &el : cnt) {
    if (el.second == 1) {
      ones.insert(el.first);
    }
  }
  vector<int> u, v, a, b;

  g.clear();
  g.resize(n);

  auto chk = [&](pair<int, int> pp) {
    cnt[pp] -= 1;
    switch (cnt[pp]) {
    case 1: {
      ones.insert(pp);
    };
    case 0: {
      ones.erase(pp);
    };
    }
  };

  auto die = [&](int i, int j) {
    if (j < i)
      swap(i, j);
    alive.erase({i, j});
    if (x[i] == x[j]) {
      pair<int, int> pp;
      pp = {x[i] + 1, (y[i] + y[j]) / 2};
      chk(pp);
      pp = {x[i] - 1, (y[i] + y[j]) / 2};
      chk(pp);
    } else {
      pair<int, int> pp;
      pp = {(x[i] + x[j]) / 2, y[i] + 1};
      chk(pp);
      pp = {(x[i] + x[j]) / 2, y[i] - 1};
      chk(pp);
    }
  };
  auto al = [&](int i, int j) {
    if (j < i)
      swap(i, j);
    return alive.count({i, j});
  };
  auto check_edge = [&](int i, int j, pair<int, int> xy) {
    if (al(i, j) && get(i) != get(j)) {
      u.push_back(i);
      v.push_back(j);
      merge(i, j);
      a.push_back(xy.first);
      b.push_back(xy.second);
      die(i, j);
    } else if (al(i, j)) {
      die(i, j);
    }
  };

  while (true) {
    while (!ones.empty()) {
      pair<int, int> xy = *ones.begin();
      ones.erase(ones.begin());
      pair<int, int> RU, RD, LD, LU;
      RU = RD = LD = LU = xy;
      RU.first++, RU.second++;
      RD.first++, RD.second--;
      LU.first--, LU.second++;
      LD.first--, LD.second--;
      size_t was = u.size();
      if (byc.count(RU) && byc.count(RD)) {
        int i = byc[RU];
        int j = byc[RD];
        check_edge(i, j, xy);
      }
      if (byc.count(RD) && byc.count(LD)) {
        int i = byc[RD];
        int j = byc[LD];
        check_edge(i, j, xy);
      }
      if (byc.count(LD) && byc.count(LU)) {
        int i = byc[LD];
        int j = byc[LU];
        check_edge(i, j, xy);
      }
      if (byc.count(LU) && byc.count(RU)) {
        int i = byc[LU];
        int j = byc[RU];
        check_edge(i, j, xy);
      }
      if (u.size() != was) {
        cnt[xy] = -100;
      }
      assert(u.size() - was <= 1);
    }
    auto alive2 = alive;
    vector<pair<int, int>> kek;
    for (auto [i, j] : alive2) {
      if (get(i) == get(j)) {
        die(i, j);
      } else {
        kek.push_back({i, j});
      }
    }
    assert(kek.size() == alive.size());
    if (ones.empty()) {
      if (alive.empty() || clock() > 3 * CLOCKS_PER_SEC)
	break;
      int ind = randint(0, kek.size() - 1);
      auto [i, j] = kek[ind];
      vector<pair<int, int>> can;
      pair<int, int> pp;
      if (x[i] == x[j]) {
	pp = {x[i] + 1, (y[i] + y[j]) / 2};
	if (cnt[pp] >= 0) {
	  can.push_back(pp);
	}
	pp = {x[i] - 1, (y[i] + y[j]) / 2};
	if (cnt[pp] >= 0) {
	  can.push_back(pp);
	}
      } else {
	pp = {(x[i] + x[j]) / 2, y[i] + 1};
	if (cnt[pp] >= 0) {
	  can.push_back(pp);
	}
	pp = {(x[i] + x[j]) / 2, y[i] - 1};
        if (cnt[pp] >= 0) {
          can.push_back(pp);
        }
      }
      if (can.empty()) {
        return 0;
      }
      pair<int, int> xy = can[randint(0, can.size() - 1)];
      u.push_back(i);
      v.push_back(j);
      merge(i, j);
      a.push_back(xy.first);
      b.push_back(xy.second);
      cnt[xy] = -100;
      die(i, j);
    }
  }

  for (int i = 0; i < (int)u.size(); i++) {
    g[u[i]].push_back(v[i]);
    g[v[i]].push_back(u[i]);
  }
  used.assign(n, 0);
  dfs(0);
  assert(*min_element(used.begin(), used.end()) == 1);

  build(u, v, a, b);
  return 1;
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 872 ms 43648 KB Output is correct
10 Correct 42 ms 4596 KB Output is correct
11 Correct 279 ms 23088 KB Output is correct
12 Correct 64 ms 6620 KB Output is correct
13 Correct 96 ms 14204 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 4 ms 844 KB Output is correct
16 Correct 869 ms 43700 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 872 ms 43648 KB Output is correct
10 Correct 42 ms 4596 KB Output is correct
11 Correct 279 ms 23088 KB Output is correct
12 Correct 64 ms 6620 KB Output is correct
13 Correct 96 ms 14204 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 4 ms 844 KB Output is correct
16 Correct 869 ms 43700 KB Output is correct
17 Correct 0 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 0 ms 204 KB Output is correct
23 Correct 2373 ms 80220 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 5 ms 716 KB Output is correct
26 Correct 7 ms 1100 KB Output is correct
27 Correct 12 ms 1456 KB Output is correct
28 Correct 788 ms 30708 KB Output is correct
29 Correct 1255 ms 47816 KB Output is correct
30 Correct 1847 ms 63688 KB Output is correct
31 Correct 2374 ms 80268 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 0 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 1 ms 204 KB Output is correct
36 Correct 0 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 0 ms 204 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct
41 Correct 0 ms 204 KB Output is correct
42 Correct 0 ms 204 KB Output is correct
43 Correct 4 ms 716 KB Output is correct
44 Correct 6 ms 1100 KB Output is correct
45 Runtime error 3057 ms 65640 KB Execution killed with signal 6
46 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 872 ms 43648 KB Output is correct
10 Correct 42 ms 4596 KB Output is correct
11 Correct 279 ms 23088 KB Output is correct
12 Correct 64 ms 6620 KB Output is correct
13 Correct 96 ms 14204 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 4 ms 844 KB Output is correct
16 Correct 869 ms 43700 KB Output is correct
17 Correct 0 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 0 ms 204 KB Output is correct
23 Correct 2373 ms 80220 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 5 ms 716 KB Output is correct
26 Correct 7 ms 1100 KB Output is correct
27 Correct 12 ms 1456 KB Output is correct
28 Correct 788 ms 30708 KB Output is correct
29 Correct 1255 ms 47816 KB Output is correct
30 Correct 1847 ms 63688 KB Output is correct
31 Correct 2374 ms 80268 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 0 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 1 ms 204 KB Output is correct
36 Correct 0 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 0 ms 204 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct
41 Correct 0 ms 204 KB Output is correct
42 Correct 0 ms 204 KB Output is correct
43 Correct 4 ms 716 KB Output is correct
44 Correct 6 ms 1100 KB Output is correct
45 Runtime error 3057 ms 65640 KB Execution killed with signal 6
46 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 872 ms 43648 KB Output is correct
10 Correct 42 ms 4596 KB Output is correct
11 Correct 279 ms 23088 KB Output is correct
12 Correct 64 ms 6620 KB Output is correct
13 Correct 96 ms 14204 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 4 ms 844 KB Output is correct
16 Correct 869 ms 43700 KB Output is correct
17 Correct 0 ms 204 KB Output is correct
18 Correct 0 ms 204 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Runtime error 3090 ms 120500 KB Execution killed with signal 6
21 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 872 ms 43648 KB Output is correct
10 Correct 42 ms 4596 KB Output is correct
11 Correct 279 ms 23088 KB Output is correct
12 Correct 64 ms 6620 KB Output is correct
13 Correct 96 ms 14204 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 4 ms 844 KB Output is correct
16 Correct 869 ms 43700 KB Output is correct
17 Correct 2001 ms 87168 KB Output is correct
18 Correct 1999 ms 91932 KB Output is correct
19 Runtime error 3089 ms 120600 KB Execution killed with signal 6
20 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 872 ms 43648 KB Output is correct
10 Correct 42 ms 4596 KB Output is correct
11 Correct 279 ms 23088 KB Output is correct
12 Correct 64 ms 6620 KB Output is correct
13 Correct 96 ms 14204 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 4 ms 844 KB Output is correct
16 Correct 869 ms 43700 KB Output is correct
17 Correct 0 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 0 ms 204 KB Output is correct
20 Correct 0 ms 204 KB Output is correct
21 Correct 0 ms 204 KB Output is correct
22 Correct 0 ms 204 KB Output is correct
23 Correct 2373 ms 80220 KB Output is correct
24 Correct 1 ms 204 KB Output is correct
25 Correct 5 ms 716 KB Output is correct
26 Correct 7 ms 1100 KB Output is correct
27 Correct 12 ms 1456 KB Output is correct
28 Correct 788 ms 30708 KB Output is correct
29 Correct 1255 ms 47816 KB Output is correct
30 Correct 1847 ms 63688 KB Output is correct
31 Correct 2374 ms 80268 KB Output is correct
32 Correct 0 ms 204 KB Output is correct
33 Correct 0 ms 204 KB Output is correct
34 Correct 0 ms 204 KB Output is correct
35 Correct 1 ms 204 KB Output is correct
36 Correct 0 ms 204 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 0 ms 204 KB Output is correct
39 Correct 0 ms 204 KB Output is correct
40 Correct 0 ms 204 KB Output is correct
41 Correct 0 ms 204 KB Output is correct
42 Correct 0 ms 204 KB Output is correct
43 Correct 4 ms 716 KB Output is correct
44 Correct 6 ms 1100 KB Output is correct
45 Runtime error 3057 ms 65640 KB Execution killed with signal 6
46 Halted 0 ms 0 KB -