Submission #299836

#	Time	Username	Problem	Language	Result	Execution time	Memory
299836		Tangent	Highway Tolls (IOI18_highway)	C++17	18 / 100	163 ms	8944 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>

using namespace std;

//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
// typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
// find_by_order(), order_of_key()

typedef long long ll;
typedef long double dd;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<dd, dd> pdd;
typedef vector<int> vii;
typedef vector<ll> vll;
typedef vector<dd> vdd;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<pdd> vpdd;
typedef vector<vii> vvii;
typedef vector<vll> vvll;
typedef vector<vdd> vvdd;
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;
typedef vector<vpdd> vvpdd;
typedef vector<bool> vb;

const int inf = 1 << 30;

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


#ifdef TEST
#define dbg(x) cout << #x << ": " << x << '\n';
#define dbgc(x) cout << #x << ":"; forin(a, x) { cout << " " << a; } cout << endl;
#define tassert(x) assert(x);
#else
#define dbg(x)
#define dbgc(x)
#define tassert(x)
#endif


void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
  int M = U.size();
  bool t3 = true;
  rep(i, M) {
    if (U[i] != i || V[i] != i + 1) {
      t3 = false;
      break;
    }
  }
  if (t3) {
    ll dist = ask(vii(M, 0)) / A;
    int lo = 0, hi = N - 1 - dist;
    while (lo < hi) {
      int mid = (lo + hi + 1) / 2;
      vii query(M, 0);
      rep(i, mid) {
        query[i] = 1;
      }
      if (ask(query) > dist * A) {
        hi = mid - 1;
      } else {
        lo = mid;
      }
    }
    answer(lo, lo + dist);
  } else if (M == N - 1) {
    vvpii adj(N);
    rep(i, M) {
      adj[U[i]].emplace_back(V[i], i);
      adj[V[i]].emplace_back(U[i], i);
    }
    vpii parent(N, {-1, -1});
    parent[0] = {-2, -2};
    vii depth(N, -1);
    depth[0] = 0;
    deque<int> q = {0};
    while (!q.empty()) {
      int u = q.front();
      q.pop_front();
      forin(p, adj[u]) {
        if (parent[p.first].first == -1) {
          parent[p.first] = {u, p.second};
          depth[p.first] = depth[u] + 1;
          q.emplace_back(p.first);
        }
      }
    }
    ll dist = ask(vii(M, 0)) / A;
    vii candidates;
    rep(i, N) {
      if (depth[i] == dist) {
        candidates.emplace_back(i);
      }
    }
    while (candidates.size() > 1) {
      vii a, b, query(M);
      rep(i, candidates.size()) {
        if (i & 1) {
          a.emplace_back(candidates[i]);
          query[parent[candidates[i]].second] = 1;
        } else {
          b.emplace_back(candidates[i]);
        }
      }
      if (ask(query) > dist * A) {
        candidates = move(a);
      } else {
        candidates = move(b);
      }
    }
    answer(0, candidates[0]);
  }
}

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:33:36: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 | #define rep(i, n) for (ll i = 0; i < n; i++)
......
  106 |       rep(i, candidates.size()) {
      |           ~~~~~~~~~~~~~~~~~~~~      
highway.cpp:106:7: note: in expansion of macro 'rep'
  106 |       rep(i, candidates.size()) {
      |       ^~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31