Submission #1006288

#	Time	Username	Problem	Language	Result	Execution time	Memory
1006288		mdub	Cave (IOI13_cave)	C++14	100 / 100	154 ms	504 KiB

cave

#include "cave.h"
#include <bits/stdc++.h>

using namespace std;

void exploreCave(int N) {
  int corrDoor[N];
  for (int i =0 ; i < N; i++) corrDoor[i] = -1;
  int switches[N];
  for (int i = 0; i < N; i++) {
    switches[i] = 0;
  }
  
  for (int door = 0; door < N; door++) {
    bool opened; bool newState;
    int left = 0; int right = N-1;
    //for (int i = 0; i < N; i++) cerr << switches[i] << " ";
    //cerr << '\n';
    if (tryCombination(switches) == door) {
    
      opened = false;
    }
    else opened = true;
    while (left < right) {
      int mid = (left + right) / 2;
      for (int i = left; i <= mid; i++) {
	if (corrDoor[i] == -1) {
	  switches[i] = (switches[i] + 1)%2;
	}
      }
      //for (int i = 0; i < N; i++) cerr << switches[i] << " ";
      //cerr << '\n';
      if (tryCombination(switches) == door) {
	newState = false;
      }
      else newState = true;
      if (newState != opened) {
	right = mid;
      }
      else {
	left = mid + 1;
      }
      opened = newState;
    }
    corrDoor[left] = door;
    if (!opened) switches[left] = (switches[left] + 1) % 2;
  }
  answer(switches, corrDoor);
}

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