Submission #186840

#	Time	Username	Problem	Language	Result	Execution time	Memory
186840		AlexPop28	Toll (BOI17_toll)	C++11	7 / 100	198 ms	47968 KiB

toll

#include <bits/stdc++.h>
#define dbg() cerr <<
#define name(x) (#x) << ": " << (x) << ' ' <<
// a doua zi dupa 11 ore de somn merge mai bine garantez eu
// ah.. sau poate ca nu.. sau?

using namespace std;

const int INF = (int)1e9 + 5;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int k, n, m, q; cin >> k >> n >> m >> q;
  int groups = (n + k - 1) / k;
  int log_groups = 32 - __builtin_clz(groups);
  vector<vector<vector<int>>> dist(log_groups,
    vector<vector<int>>(n,
      vector<int>(k, INF)));
  vector<vector<pair<int, int>>> adj(n);
  for (int i = 0; i < m; ++i) {
    int a, b, c; cin >> a >> b >> c;
    adj[a].emplace_back(b, c);
    adj[b].emplace_back(a, c);
    dist[0][a][b % k] = c;
  }
  
  for (int p = 1; p < log_groups; ++p) {
    for (int from = 0; from / k + (1 << p) <= (n - 1) / k; ++from) {
      int lim = k;
      if ((from / k + (1 << p)) == (n - 1) / k) lim = (n - 1) % k;
      for (int to = 0; to < lim; ++to) {
        int gr = from / k + (1 << (p - 1));
        int lst = min((gr + 1) * k, n);
        for (int x = gr * k, r = 0; x < lst; ++x, ++r) {
          dist[p][from][to] = min(dist[p][from][to],
            dist[p - 1][from][r] + dist[p - 1][x][to]);
        }
      }
    }
  }

//  function<int(int, int, int)> GetCost = [&](int from, int to, int max_bit) {
//    int ans = INF;
//    for (int bit = max_bit - 1; bit >= 0; --bit) {
//      int gr = from / k + (1 << bit);
//      if (gr > to / k) continue;
//      if (gr == to / k) {
//        return dist[bit][from][to % k];
//      }
//      for (int x = gr * k, r = 0; x < (gr + 1) * k; ++x, ++r) {
//        int res = dist[bit][from][r];
//        if (res == INF) continue;
//        res += GetCost(x, to, bit);
//        ans = min(ans, res);
//      }
//      break; 
//    }
//    return ans;
//  };
  
  while (q--) {
    int a, b; cin >> a >> b;
    vector<int> d(k, INF);
    d[a % k] = 0;
    a = a / k;
    int len = b / k - a;
    for (int bit = 0; (1 << bit) <= len; ++bit) {
      if (((1 << bit) & len) == 0) continue;
      vector<int> nd(k, INF);
      for (int from = a * k; from < (a + 1) * k; ++from) {
        for (int x = 0; x < k; ++x) {
          nd[x] = min(nd[x], d[from - a * k] + dist[bit][from][x]);
        }
      }
      a += 1 << bit;
      d = move(nd);
    }
    int ans = d[b % k];
    if (ans == INF) ans = -1;
    cout << ans << '\n';
  }
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44