10703 - Free spots

[Martin Macko]

Suppose you have a rectangular grid drawn on a paper. You draw some filled rectangles on the paper. Your task is to find the area that is not filled.

Code: Select all

5 5 2
1 1 3 2
3 0 3 5

For this input the grid would be like this ("." empty, "F" filled)

Code: Select all

  12345
1 ..F..
2 .FFF.
3 .FFF.
4 ..F..
5 ..F..

And answer would be 16.

[mohsincsedu]

Hello All.....
May be i do not understand What the problem says!!!!!!!!
Plz explain.
I got WA.
here is my coding:

Code: Select all

int W,H,N,i,j,x1,x2,y1,y2,k,max_x,min_x,max_y,min_y;
	long long count;

	while(scanf("%d %d %d",&W,&H,&N)==3)
	{
		if(!W&&!H&&!N)
			break;
		for(i = 0; i < W; i++)
			for(j = 0; j < H; j++)
				board[i][j] = '0';
		for(k = 0; k < N; k++ )
		{
			scanf("%d %d %d %d",&x1,&y1,&x2,&y2);
			if(x1>x2)
			{
				max_x = x1;
				min_x = x2;
			}
			else
			{
				max_x = x2;
				min_x = x1;
			}
			if(y1>y2)
			{
				max_y = y1;
				min_y = y2;
			}
			else
			{
				max_y = y2;
				min_y = y1;
			}
			for(i = min_x; i < max_x; i++)
			{
				for(j = min_y; j < max_y; j++)
				{
					board[i][j] = '1';
				}
			}
		}
		count = 0;
		for(i = 0; i < W; i++)
			for(j = 0; j < H; j++)
				if(board[i][j]=='0')
					count++;
		if(!count)
			printf("There is no empty spots.\n");
		else if(count==1)
			printf("There is one empty spot.\n");
		else
			printf("There is %lld empty spots.\n",count);
	}

[Cho]

It will fail with this:
2 2 1
1 1 1 1
0 0 0
Output:
3

But I don't think you code can pass the sample io. And even you submit it, you should get TLE intead of WA.

[mohsincsedu]

hi Cho..
I do not understant!!!! Why TLE???
i changed my code:
But WA

Code: Select all

for(i = min_x-1; i < max_x; i++) 
         { 
            for(j = min_y-1; j < max_y; j++) 
            { 
               board[i][j] = '1'; 
            } 
         } 

Plz help me!!!:(

[Solaris]

Your code Shows

There is 83470 empty spots.

Try by changing is to are

[mohsincsedu]

Thanks Solaris.................................
I got Acc..

I always follow your Advice..

):)):))

[xintactox]

I did the following algorthm to get AC:

1) Initialized an array of bool board[500][500], all true;
2)Read the sub_boards. This is an important point, because X1,Y1,X2,Y2 are NOT NECESSARILY given in that order. So you need to swap X1 and X2 if X1 > X2, and swap Y1 and Y2 if Y1 if Y1 > Y2.
3) With 2 nested loops I marked each sub_board, marking false into each position of the main board. Start at x1,y1 and go through the board until u reach x2, y2;
4) After that, just scan the board with two loops, counting the number of positions setted to true.
5) Pay attention to the format of the output.
Zero "true positions" means
There is no empty spots.
One "true position" means
There is one empty spots.
More than one "true positions" means
There are <true positions> empty spots.

And Be Happy!

[altaf hussain(sust_2002)]

hi,
i am getting WA in that problem.
my program generates good ans for all the inputs in the board.
will any one help me.
here is my code:

Code: Select all

#include<stdio.h>
#define sz 502

int main()
{
	long arr[sz][sz],w,h,sub,s,i,j,x1,y1,x2,y2,flag=0,temp,count;
	while(scanf("%ld %ld %ld",&w,&h,&sub)==3 && (w!=0 ||h!=0 || sub!=0 ))
	{		
		for(i=1;i<=w;i++)
			for(j=1;j<=h;j++)
				arr[i][j]=1;
		count = 0;
		for(s=0;s<sub;s++)
		{
			scanf("%ld %ld %ld %ld",&x1,&y1,&x2,&y2);
			if(x1>x2)
			{
				temp =x2;
				x2=x1;
				x1=temp;
			}
			if(y1>y2)
			{
				temp =y2;
				y2=y1;
				y1=temp;
			}
			for(i=x1;i<=x2;i++)
				for(j=y1;j<=y2;j++)
					arr[i][j]=0;
		}
		for(i=1;i<=w;i++)
			for(j=1;j<=h;j++)
				if(arr[i][j]==1)
					count++;
		if(count==0)
			printf("There is no empty spots.\n");
		else if(count==1)
			printf("There is one empty spots.\n");
		else
			printf("There are %ld empty spots.\n",count);
	}
	return 0;
}

waiting for reply:

[Mushfiqur Rahman]

Altaf Wrote

hi,
i am getting WA in that problem.
my program generates good ans for all the inputs in the board.
will any one help me.
here is my code:

I found your bug. The problem is in the following line

"else if(count==1)
printf("There is one empty spots.\n");


You should check the output format for output "one" .

[kolpobilashi]

i am getting tired can't find out the bug....i think my outputs are also ok.plz anyone help....

Code: Select all

cut..

[Jan]

Try the following I/O set..

Input:

Code: Select all

500 500 0
0 0 0

Output:

Code: Select all

There are 250000 empty spots.

Hope it helps.

[kolpobilashi]

thanx a lot JAN...didn think abt that input...