Submission #1042024

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042024		izanbf	Tropical Garden (IOI11_garden)	C++14	69 / 100	5074 ms	47188 KiB

garden

#include "garden.h"
#include "gardenlib.h"
#include <bits/stdc++.h>

using namespace std;

void count_routes(int N, int M, int P, int R[][2], int Q, int G[])
{
  vector<vector<int>> adj(N);
  for (int i = 0; i < M; ++i) {
    adj[R[i][0]].push_back(R[i][1]);
    adj[R[i][1]].push_back(R[i][0]);
  }

  auto node = [&](int u, int v) {
    if (adj[v][0] == u)
      return N+v;
    else
      return v;
  };

  const int J = 29;
  vector<vector<int>> succ(J+1, vector<int>(2*N, -1));
  for (int i = 0; i < N; ++i) {
    succ[0][node(-1, i)] = node(i, adj[i][0]);
    for (int v : adj[i]) {
      if (v != adj[i][0] or adj[i].size() == 1)
        succ[0][node(v, i)] = node(i, adj[i][0]);
      else
        succ[0][node(v, i)] = node(i, adj[i][1]);
    }
  }

  for (int j = 1; j <= J; ++j) {
    for (int u = 0; u < 2*N; ++u) {
      succ[j][u] = succ[j-1][ succ[j-1][u] ];
    }
  }

  for(int it = 0; it < Q; ++it) {
    int K = G[it];
    int cnt = 0;

    for (int i = 0; i < N; ++i) {
      int u = node(-1, i);
      
      for (int j = J; j >= 0; --j) {
        if (K & (1 << j)) u = succ[j][u];
      }

      if (u == P or u == N+P) ++cnt;
    }

    answer(cnt);
  }
}

• Subtask 1: 49 / 49
• Subtask 2: 20 / 20
• Subtask 3: 0 / 31