Submission #1112806

#	Time	Username	Problem	Language	Result	Execution time	Memory
1112806		julia_08	Cave (IOI13_cave)	C++17	100 / 100	189 ms	592 KiB

cave

#include "cave.h"

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 5e3 + 10;

int door[MAXN], position[MAXN], marc[MAXN];

bool p(int i, int j, int cur_door){

  for(int k=i; k<=j; k++){
    if(!marc[k]){
      position[k] = 1 - position[k];
    }
  }

  int ans = tryCombination(position);

  for(int k=i; k<=j; k++){
    if(!marc[k]){
      position[k] = 1 - position[k];
    }
  }

  return (ans == cur_door);
}

int bs(int n, int cur_door){
  int l = 0, r = n - 1;

  while(l < r){
    int m = l + (r - l) / 2;

    if(p(l, m, cur_door)) r = m;
    else l = m + 1;
  }

  return r;
}

void exploreCave(int n){

  for(int i=0; i<n; i++){

    if(tryCombination(position) == i){

      for(int j=0; j<n; j++){
        if(!marc[j]){
          position[j] = 1 - position[j];
        }
      }

    }

    int x = bs(n, i);

    door[x] = i;
    marc[x] = 1;

  }

  answer(position, door);

}

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