Submission #151096

#	Time	Username	Problem	Language	Result	Execution time	Memory
151096		joseacaz	Cave (IOI13_cave)	C++17	100 / 100	1192 ms	640 KiB

cave

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

using namespace std;

// Main
//	int tryCombination(int N, int S[])
//	void answer(int N, int S[], int D[])


void exploreCave ( int N )
{
	int s, e, mid, val, res, ans;
	int aux[N], S[N], D[N];
	for ( int i = 0; i < N; i++ )
		S[i] = -1, D[i] = -1;

	for ( int i = 0; i < N; i++ )
	{
		for ( int j = 0; j < N; j++ )
			if ( S[j] == -1 )
				aux[j] = 0;
		ans = tryCombination ( aux );
		
		if ( ans == i )
		{
			//the door opens with 1's

			s = 0, e = N - 1;
			while ( s <= e )
			{
				mid = (s + e) / 2;

				for ( int k = 0; k <= mid; k++ )
					if ( S[k] == -1 )
						aux[k] = 1;
				for ( int k = mid + 1; k < N; k++ )
					if ( S[k] == -1 )
						aux[k] = 0;

				ans = tryCombination ( aux );
				val = (ans == i ? 0 : 1 );
				
				if ( val )
					res = mid, e = mid - 1;
				else
					s = mid + 1;
			}
			
			aux[res] = 1;
			S[res] = 1;
			D[res] = i;
		}
		else
		{
			//the door opens with 0's
			s = 0, e = N - 1;
			while ( s <= e )
			{
				mid = (s + e) / 2;

				for ( int k = 0; k <= mid; k++ )
					if ( S[k] == -1 )
						aux[k] = 0;
				for ( int k = mid + 1; k < N; k++ )
					if ( S[k] == -1 )
						aux[k] = 1;
				
				ans = tryCombination ( aux );
				val = (ans == i ? 0 : 1 );
				
				if ( val )
					res = mid, e = mid - 1;
				else
					s = mid + 1;
			}
			
			aux[res] = 0;
			S[res] = 0;
			D[res] = i;
		}
	}
	
	answer ( S, D );
}

Compilation message (stderr)

cave.cpp: In function 'void exploreCave(int)':
cave.cpp:50:13: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
    aux[res] = 1;
    ~~~~~~~~~^~~

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