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Submission #423994

# Submission time Handle Problem Language Result Execution time Memory
423994 2021-06-11T15:07:31 Z Tangent Highway Tolls (IOI18_highway) C++17
51 / 100
 369 ms 262148 KB 
#include "highway.h"
#include "bits/stdc++.h"

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vii;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vii> vvii;
typedef vector<vll> vvll;
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;

#define ffor(i, a, b) for (ll i = a; i < b; i++)
#define rep(i, n) ffor(i, 0, n)
#define forin(x, a) for (auto &x: a)
#define all(a) a.begin(), a.end()

pii solve(int N, std::vector<int> U, std::vector<int> V, int A, int B, vii &verts, int vertcount) {
  int M = U.size();
  vvpii adj(N);
  rep(i, M) {
    if (verts[U[i]] && verts[V[i]]) {
      adj[U[i]].emplace_back(V[i], i);
      adj[V[i]].emplace_back(U[i], i);
    }
  }

  vii cnt(N, 1), depth(N), pedge(N, -1);
  vvpii children(N);

  function<void(int, int)> dfs;
  dfs = [&](int x, int p) {
    forin(y, adj[x]) {
      if (y.first != p) {
        children[x].emplace_back(y);
        depth[y.first] = depth[x] + 1;
        pedge[y.first] = y.second;
        dfs(y.first, x);
        cnt[x] += cnt[y.first];
      }
    }
  };
  rep(i, N) {
    if (verts[i]) {
      dfs(i, -1);
      break;
    }
  }
  int root = -1, bestmax = N;
  rep(i, N) {
    if (!verts[i]) continue;
    int currmax = vertcount - cnt[i];
    forin(j, children[i]) {
      currmax = max(currmax, cnt[j.first]);
    }
    if (currmax < bestmax) {
      root = i;
      bestmax = currmax;
    }
  }

  cnt.assign(N, 1);
  depth.assign(N, 0);
  pedge.assign(N, -1);
  children.clear();
  children.resize(N);
  dfs(root, -1);

  vii query(M);
  ll dist = ask(query) / A;
  forin(child, children[root]) {
    query[child.second] = 1;
  }
  ll rootans = (ask(query) - (A * dist)) / (B - A);
  forin(child, children[root]) {
    query[child.second] = 0;
  }

  if (rootans == 0) {
    vvii egroups(children[root].size());
    rep(i, children[root].size()) {
      deque<int> q = {children[root][i].first};
      while (!q.empty()) {
        forin(child, children[q.front()]) {
          q.emplace_back(child.first);
          egroups[i].emplace_back(child.second);
        }
        q.pop_front();
      }
    }

    int lo = 0, hi = egroups.size() - 1;
    while (lo < hi) {
      vii query2(M);
      int mid = (lo + hi + 1) / 2;
      ffor(i, lo, mid) {
        forin(e, egroups[i]) {
          query2[e] = 1;
        }
      }
      if (ask(query2) > dist * A) {
        hi = mid - 1;
      } else {
        lo = mid;
      }
    }
    vii nverts(N);
    int nvertcount = 0;
    deque<int> q = {children[root][lo].first};
    while (!q.empty()) {
      nverts[q.front()] = 1;
      nvertcount++;
      forin(child, children[q.front()]) {
        q.emplace_back(child.first);
      }
      q.pop_front();
    }
    return solve(N, U, V, A, B, nverts, nvertcount);
  } else if (rootans == 1) {
    vii cand;
    rep(i, N) {
      if (verts[i] && depth[i] == dist) {
        cand.emplace_back(i);
      }
    }
    int lo = 0, hi = cand.size() - 1;
    while (lo < hi) {
      vii query2(M);
      int mid = (lo + hi + 1) / 2;
      ffor(i, lo, mid) {
        query2[pedge[cand[i]]] = 1;
      }
      if (ask(query2) > dist * A) {
        hi = mid - 1;
      } else {
        lo = mid;
      }
    }
    return {root, cand[lo]};
  } else {
    int lo = 0, hi = children[root].size() - 1;
    vii child_inds, res;
    while (lo < hi) {
      vii query2(M);
      int mid = (lo + hi + 1) / 2;
      ffor(i, lo, mid) {
        query2[children[root][i].second] = 1;
      }
      ll childans = (ask(query2) - (A * dist)) / (B - A);
      if (childans == 0) {
        lo = mid;
      } else if (childans == 1) {
        int lo1 = lo, hi1 = mid - 1, lo2 = mid, hi2 = hi;
        while (lo1 < hi1) {
          vii query3(M);
          int mid1 = (lo1 + hi1 + 1) / 2;
          ffor(i, lo1, mid1) {
            query3[children[root][i].second] = 1;
          }
          if (ask(query3) > dist * A) {
            hi1 = mid1 - 1;
          } else {
            lo1 = mid1;
          }
        }
        while (lo2 < hi2) {
          vii query3(M);
          int mid2 = (lo2 + hi2 + 1) / 2;
          ffor(i, lo2, mid2) {
            query3[children[root][i].second] = 1;
          }
          if (ask(query3) > dist * A) {
            hi2 = mid2 - 1;
          } else {
            lo2 = mid2;
          }
        }
        child_inds = {lo1, lo2};
        break;
      } else {
        hi = mid - 1;
      }
    }
    forin(ind, child_inds) {
      vii query2(M);
      vii vgroup;
      deque<int> q = {children[root][ind].first};
      while (!q.empty()) {
        vgroup.emplace_back(q.front());
        forin(child, children[q.front()]) {
          q.emplace_back(child.first);
          query2[child.second] = 1;
        }
        q.pop_front();
      }
      ll cdist = (ask(query2) - (dist * A)) / (B - A);
      vii cand;
      forin(i, vgroup) {
        if (depth[i] == cdist + 1) {
          cand.emplace_back(i);
        }
      }
      int lo1 = 0, hi1 = cand.size() - 1;
      while (lo1 < hi1) {
        vii query3(M);
        int mid1 = (lo1 + hi1 + 1) / 2;
        ffor(i, lo1, mid1) {
          query3[pedge[cand[i]]] = 1;
        }
        if (ask(query3) > dist * A) {
          hi1 = mid1 - 1;
        } else {
          lo1 = mid1;
        }
      }
      res.emplace_back(cand[lo1]);
    }
    return {res[0], res[1]};
  }
}


void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
  vii curr(N, 1);
  auto res = solve(N, U, V, A, B, curr, N);
  answer(res.first, res.second);
}

Compilation message

highway.cpp: In function 'pii solve(int, std::vector<int>, std::vector<int>, int, int, vii&, int)':
highway.cpp:18:40: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 | #define ffor(i, a, b) for (ll i = a; i < b; i++)
      |                                        ^
highway.cpp:19:19: note: in expansion of macro 'ffor'
   19 | #define rep(i, n) ffor(i, 0, n)
      |                   ^~~~
highway.cpp:86:5: note: in expansion of macro 'rep'
   86 |     rep(i, children[root].size()) {
      |     ^~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 200 KB Output is correct
2 Correct 1 ms 200 KB Output is correct
3 Correct 1 ms 200 KB Output is correct
4 Correct 1 ms 200 KB Output is correct
5 Correct 1 ms 200 KB Output is correct
6 Correct 1 ms 200 KB Output is correct
7 Correct 1 ms 200 KB Output is correct
8 Correct 1 ms 200 KB Output is correct
9 Correct 1 ms 200 KB Output is correct
10 Correct 1 ms 200 KB Output is correct
11 Correct 1 ms 200 KB Output is correct
12 Correct 1 ms 200 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 22 ms 2752 KB Output is correct
3 Correct 258 ms 30856 KB Output is correct
4 Correct 176 ms 14692 KB Output is correct
5 Correct 193 ms 14584 KB Output is correct
6 Correct 257 ms 14572 KB Output is correct
7 Correct 227 ms 14380 KB Output is correct
8 Correct 256 ms 22300 KB Output is correct
9 Correct 233 ms 14464 KB Output is correct
10 Correct 250 ms 22768 KB Output is correct
11 Correct 279 ms 33856 KB Output is correct
12 Correct 305 ms 27744 KB Output is correct
13 Correct 253 ms 26924 KB Output is correct
14 Correct 206 ms 16564 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 7140 KB Output is correct
2 Correct 40 ms 7516 KB Output is correct
3 Correct 66 ms 29936 KB Output is correct
4 Correct 150 ms 23156 KB Output is correct
5 Correct 233 ms 82784 KB Output is correct
6 Correct 106 ms 23204 KB Output is correct
7 Correct 228 ms 89416 KB Output is correct
8 Correct 99 ms 23276 KB Output is correct
9 Correct 151 ms 32868 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 328 KB Output is correct
2 Correct 19 ms 1856 KB Output is correct
3 Correct 163 ms 27736 KB Output is correct
4 Correct 268 ms 30692 KB Output is correct
5 Correct 249 ms 43528 KB Output is correct
6 Correct 328 ms 44240 KB Output is correct
7 Correct 259 ms 56032 KB Output is correct
8 Correct 273 ms 57064 KB Output is correct
9 Correct 207 ms 14700 KB Output is correct
10 Correct 184 ms 14708 KB Output is correct
11 Correct 212 ms 16520 KB Output is correct
12 Correct 243 ms 18080 KB Output is correct
13 Correct 219 ms 17440 KB Output is correct
14 Correct 254 ms 26924 KB Output is correct
15 Correct 249 ms 58580 KB Output is correct
16 Correct 335 ms 57984 KB Output is correct
17 Correct 199 ms 17768 KB Output is correct
18 Correct 283 ms 25564 KB Output is correct
19 Correct 292 ms 58144 KB Output is correct
20 Correct 369 ms 50156 KB Output is correct
21 Correct 162 ms 13656 KB Output is correct
22 Correct 130 ms 13652 KB Output is correct
23 Correct 126 ms 14216 KB Output is correct
24 Correct 125 ms 15224 KB Output is correct
25 Correct 258 ms 22140 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 314 ms 262148 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Runtime error 284 ms 262148 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -