Submission #116555

#	Time	Username	Problem	Language	Result	Execution time	Memory
116555		dragonslayerit	Tropical Garden (IOI11_garden)	C++14	49 / 100	73 ms	23672 KiB

garden

#include "garden.h"
#include "gardenlib.h"
#include <vector>
#include <queue>
#include <cstdio>

const int INF=1e9+7;

static std::vector<int> adj[100005];
static int to[200005];
static std::vector<int> from[200005];

static int dist[2][200005];

static void bfs(int start,int* dist){
  std::queue<int> q;
  q.push(start);
  while(!q.empty()){
    int node=q.front();
    q.pop();
    for(int child:from[node]){
      if(!dist[child]){
	dist[child]=dist[node]+1;
	q.push(child);
      }
    }
  }
}

void count_routes(int N, int M, int P, int R[][2], int Q, int G[])
{
  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]);
  }
  /*
  for(int i=0;i<N;i++){
    printf("adj[%d][0]=%d\n",i,adj[i][0]);
    if(adj[i].size()>1){
      printf("adj[%d][1]=%d\n",i,adj[i][1]);
    }
  }
  */
  for(int i=0;i<N;i++){
    to[i<<1]=(adj[i][0]<<1)|(i==adj[adj[i][0]][0]);
    if(adj[i].size()>1){
      to[i<<1|1]=(adj[i][1]<<1)|(i==adj[adj[i][1]][0]);
    }else{
      to[i<<1|1]=to[i<<1];
    }
  }
  /*
  for(int i=0;i<N*2;i++){
    fprintf(stderr,"to[%d,%d]=%d,%d\n",i>>1,i&1,to[i]>>1,to[i]&1);
  }
  */
  for(int i=0;i<N*2;i++){
    from[to[i]].push_back(i);
  }
  bfs(P<<1,dist[0]);
  bfs(P<<1|1,dist[1]);
  int cycle[2];
  cycle[0]=dist[0][P<<1]?dist[0][P<<1]:INF;
  cycle[1]=dist[1][P<<1|1]?dist[1][P<<1|1]:INF;
  /*
  for(int i=0;i<N*2;i++){
    fprintf(stderr,"dist[%d,%d]=%d\n",i>>1,i&1,dist[0][i]);
  }
  */
  for(int q=0; q<Q; q++){
    int K=G[q];
    int ans=0;
    for(int i=0;i<N;i++){
      /*
      int x=i<<1;
      for(int k=0;k<K;k++){
	x=to[x];
      }
      if((x>>1)==P){
	ans++;
      }
      */
      
      if(dist[0][i<<1]) ans+=(K>=dist[0][i<<1]&&(K-dist[0][i<<1])%cycle[0]==0);
      if(dist[1][i<<1]) ans+=(K>=dist[1][i<<1]&&(K-dist[1][i<<1])%cycle[1]==0);
    }
    answer(ans);
  }
}

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