Submission #116935

#	Time	Username	Problem	Language	Result	Execution time	Memory
116935		dragonslayerit	Cave (IOI13_cave)	C++14	100 / 100	902 ms	516 KiB

cave

#include "cave.h"

int combo[5005];
int base[5005];
int door[5005];
int n;

bool check(int len,int target){
  for(int i=0;i<n;i++){
    combo[i]=base[i];
    if(i<len&&door[i]==-1){
      combo[i]^=1;
    }
  }
  return tryCombination(combo)!=target;
}
  

void exploreCave(int N) {
  n=N;
  for(int i=0;i<N;i++){
    door[i]=-1;
  }
  for(int i=0;i<N;i++){
    if(tryCombination(base)!=i){
      for(int j=0;j<N;j++){
	if(door[j]==-1){
	  base[j]^=1;
	}
      }
    }
    int low=0,high=N;
    while(high-low>1){
      int mid=(low+high)/2;
      if(check(mid,i)){
	high=mid;
      }else{
	low=mid;
      }
    }
    door[low]=i;
    base[low]^=1;
  }
  answer(base,door);
}

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24