416 - LED Test

[Ivor]

Are there any tricky inputs or possible pitfalls?
I'm starting to become hopeless.
I've solved it, resolved, revised, found some bugs but still can't get it accepted.

Any help is appreciated,
Ivor

[sumrnot]

Hmm... my first mistake was counting up, second was wrapping
No third
--
Geoff

[Ivor]

Thanks, I have already solved it. I just didn't mark the burned segments -- a problem with understanding.

Ivor

[chuck]

Is the "count down" sequence abled to be wrapping?
Like "1 0 9 8"

[Dominik Michniewski]

I think no ....
But yoy must check this situation:
when you test i.e. 8 some segment was bad
and when you test 7 the same segment is good ... that's incorrect

Regards
Dominik

[Sedefcho]

Hi all,

I don't understand this problem. What do they actually
want us to check ? As this is the only thread dedicated to
problem 416, I am posting my question here.

Can someone explain with some plain words
the problem / not the solution just the problem /

One more thing. Currently I have a program which just
reads the input lines ( the 7-letter strings of Y/N symbols )
and then prints the numbers which they represent.
If some string represents no valid number I print "null".
The output for different datasets are separated by a line
containing the string "=================".

Using the sample input from the Problem Description I get
the following output.

Code: Select all

=================
9
=================
null null
=================
8 8
=================
6 5 4
=================
null null null
=================
null null null
=================
8 1 null null
=================
null null null

So ... Can someone explain or give some hint at least ?

[Raiyan Kamal]

I hope Sedefcho has already solved the problem.

As Sedefcho said, since "this is the only thread dedicated to problem 416", i am posting some explanation for the future sufferers.

The status of the 7 LEDs is given for some count down sequence and we have to determine if this is a valid countdown sequence or not. The confusing part is the 'burnig out' of LEDs. Say the first number of the sequece is 8, then the proper status of the LEDs should be YYYYYYY. However, if the last two LEDs are bunred out then we shall see YYYYYNN. So this is also valid if we consider the last two LEDs already damaged. The next number 7, should have been seen like this : YYYNNNN and this is what we are going to see even if the last two LEDs are damaged. The next number 6 should have been : YNYYYYY and this is what we see since the last two LEDs are damaged : YNYYYNN. Next number is 5 and should have been : YNYYNYY but since the last two LEDs are damaged, we shall see YNYYNNN. And so on upto 0. Now, according to the above discussion, if the input is :
YYYYYNN
YYYNNNN
YNYYYNN
YNYYNNN

then the output should be "MATHCH" since it represents a valid sequence starting at 8 and ending at 5 with two LEDs being damaged from the beginning.

LEDs could have been damaged in the middle of the sequence too. So you have to keep that in mind. Finally, no damaged LED will become well again, so once you assume a certain LED to be damaged and it gets Y somewhere in the sequence then a contradiction arises. Keep that in mind too.

[Jan]

Raiyan, My accepted code returns MISMATCH for the input

YYYYYNN
YYYNNNN
YYYYYNN
YNYYNNN

There is no wrapping around I think.

[Raiyan Kamal]

My mistake!

I apologize. I have corrected the sample input in my previous post. Thanks to Jan for pointin out the error. I had to write 6 on the third line of input, but by mistake wrote something that looks like 1 in bangla !

Here are some more test cases.

INPUT :

Code: Select all

4
YYYYYNN
YYYNNNN
YNYYYNN
YNYYNNN
5
YYYYYYY
NNNNNNN
NNNNNNN
NNNNNNN
NNNNNNN
1
YYYYYYY
1
NNNNNNN
4
YYYYYNN
YYYNNNN
YYYYYNN
YNYYNNN
2
YYYYYYY
NNNNYYY
2
YYYNNNN
YYYNNNN
2
YNNYNNY
YNNYNNY
10
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
10
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNYNNNN
NNNNNNN
NNYNNNN
NNYNNNN

OUTPUT :

Code: Select all

MATCH
MATCH
MATCH
MATCH
MISMATCH
MISMATCH
MATCH
MATCH
MISMATCH
MATCH

[Jan]

Raiyan, I think you have made the problem so clear that there is no need of any more threads. You made it perfect. Thanks...

Good Luck!
NDC group 2...Finally we met.

[Raiyan Kamal]

Thats one of the specialities of being a Notre Damian. Thanks again. Hope to meet you again soon.

[KimKun]

#include <fstream.h>
char led[10][8] = {
"YYYYYYN",
"NYYNNNN",
"YYNYYNY",
"YYYYNNY",
"NYYNNYY",
"YNYYNYY",
"YNYYYYY",
"YYYNNNN",
"YYYYYYY",
"YYYYNYY"};
char data[100][8];
int n;
int ous[4000000];
int BT(int bun){
int error[8];
int i,flag,j,k;
for (i=bun,k=0;k<n;i--,k++){
if (i==-1) i=9;
if (k==10) k=0;
for (j=flag=0;j<7;j++){
if (led[j] != data[k][j] && data[k][j] == 'Y'){
return 1;
}else if (led[j] != data[k][j] && data[k][j] == 'N'){
error[j]=1;
}else if (error[j] == 1 && data[k][j] =='Y'){
return 1;
}
}
}
return 0;
}
int main()
{
int i,j,k;
int flag;
int qflag,eflag;
for (k=0;;k++){
eflag=0;
cin >> n;
if (n==0) break;
for (i=0;i<n;i++){
cin >> data;
}
for (i=9;i>=0;i--){
for (j=flag=0;j<7;j++){
if (led[j] != data[0][j] && data[0][j] == 'Y'){
flag=1;
break;
}
}
if (flag==0){
qflag=BT(i);
if (qflag==0){
ous[k] = 1;
eflag=1;
break;
}
}
}
}
for (i=0;i<k;i++){
if (ous==0){
cout << "MISMATCH\n";
}else{
cout << "MATCH\n";
}
}
return 0;
}



what should I do ?.T.T
Help..

[kenneth_cwc]

Anyone can help me? I tried to debug for long time

Code: Select all

#include<iostream>
using namespace std;

void check_and_store(char str[], int pos, int possible_no[]);

void main()
{
	int possible_no[10];
	int n;
	char tmp[8];
	int i, j;
	bool match;

	cin>>n;
	cin.getline(tmp, 8);
	while(n)
	{
		if(n==1)
		{
			cin.getline(tmp, 8);
			cout<<"MATCH\n";
		}
		else
		{
			for(i=0;i<n;i++)
			{
				cin.getline(tmp, 8);
				check_and_store(tmp, i, possible_no);
			}

			i=11-n;
			while(1)
			{
				match=1;

				i--;
				while(!(possible_no[n-1] & 1<<i) && i>=0)
					i--;

				if(i==-1)
				{
					match=0;
					break;
				}

				for(j=0;j<n-1;j++)
				{
					if((possible_no[n-2-j] & 1<<(i+j+1)) != 1<<(i+j+1))
						match=0;
				}

				if(match)
					break;
			}
			if(match)
				cout<<"MATCH\n";
			else
				cout<<"MISMATCH\n";
		}
		cin>>n;
		cin.getline(tmp, 8);
	}
}

void check_and_store(char str[], int pos, int possible_no[])
{
	//check 0~9:
	possible_no[pos]=1023;

	if(str[0]=='Y')
		possible_no[pos] &= ~(1<<1) & ~(1<<4);
	if(str[1]=='Y')
		possible_no[pos] &= ~(1<<5) & ~(1<<6);
	if(str[2]=='Y')
		possible_no[pos] &= ~(1<<2);
	if(str[3]=='Y')
		possible_no[pos] &= ~(1<<1) & ~(1<<4) & ~(1<<7);
	if(str[4]=='Y')
		possible_no[pos] &= ~(1<<1) & ~(1<<3) & ~(1<<4) & ~(1<<5) & ~(1<<7) & ~(1<<9);
	if(str[5]=='Y')
		possible_no[pos] &= ~(1<<1) & ~(1<<2) & ~(1<<3) & ~(1<<7);
	if(str[6]=='Y')
		possible_no[pos] &= ~(1<<0) & ~(1<<1) & ~(1<<7);

}

[Jan]

Sorry for posting wrong output.

[Jan]

You can find some test cases in the following forum. Use it.

http://online-judge.uva.es/board/viewto ... hlight=416

Hope it helps.