## 11550 - Demanding Dilemma

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rij
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Joined: Mon Nov 03, 2008 3:59 am
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### 11550 - Demanding Dilemma

pls give me some test cases.i m getting wa.
heres my code

Code: Select all

Last edited by rij on Tue Nov 04, 2008 11:48 am, edited 1 time in total.

zhouerjin
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Posts: 5
Joined: Wed Oct 01, 2008 4:52 pm

### Re: 11550 - Demanding Dilemma

I WA too...-_-!
but I can't understand your code on:if(arr[j]=='1'&& i!=j)count++;
why do you check if i!=j? I think it doesn't need...

mmonish
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### Re: 11550 - Demanding Dilemma

try this case
Input:

Code: Select all

1
3 2
1 1
1 0
0 1
My AC output:

Code: Select all

Yes
hope this helps..

rij
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### Re: 11550 - Demanding Dilemma

corrected but still wa

Code: Select all

void call(int n,int m){
int count=0,fc=0;
for(int j=0;j<m;j++){
count=0;
for(int i=0;i<n;i++){
if(arr[i][j]=='1')count++;
}
if(count==2)
fc++;
}
if(fc==m)
cout<<"Yes"<<endl;
else cout<<"No"<<endl;
return;
}

Vytenis
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### Re: 11550 - Demanding Dilemma

You must also check if there are no two identical edges defined by the incidence matrix. If there are, you should return "No".

rij
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### Re: 11550 - Demanding Dilemma

thanks got ac after a number of tries.

zhouerjin
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### Re: 11550 - Demanding Dilemma

rij wrote:thanks got ac after a number of tries.
can you say more detail?
I still WA...

SerailHydra
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Joined: Mon Oct 20, 2008 6:26 am

### Re: 11550 - Demanding Dilemma

The graph should be a simple indirected one.

Pay attention to the word 'simple'.

zhouerjin
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Posts: 5
Joined: Wed Oct 01, 2008 4:52 pm

### Re: 11550 - Demanding Dilemma

I still WA....I need help...

Code: Select all

void prepare()
{
scanf("%d%d",&n,&m);
for (int i=1;i<=n;i++)
for (int j=1;j<=n;j++)
flag[i][j]=false;
for (int i=1;i<=n;i++)
for (int j=1;j<=m;j++)
scanf("%d",&map[i][j]);
}

bool work()
{
for (int i=1;i<=m;i++)
{
int u=-1,v=-1;
for (int j=1;j<=n;j++)
if (map[j][i])
{
if (u==-1) u=j;else
if (v!=-1) return false;else v=j;
}
if (u*v<0) return false;
if (flag[u][v]) return false;
flag[u][v]=flag[v][u]=true;
}
return true;
}

shakil
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Posts: 74
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### Re: 11550 - Demanding Dilemma

To : zhouerjin
Change only one line & i hope that will make you AC.

Code: Select all

if (u*v<0) return false;
change to ->

Code: Select all

if (u==-1||v==-1) return false;
Because if u & v two are -1 then u*v>0
SHAKIL

@li_kuet
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Posts: 44
Joined: Fri May 25, 2012 6:22 pm

### Re: 11550 - Demanding Dilemma

This is a very simple problem.
Just check if every column(edge) has exactly two vertex and no two columns(edges) has same vertexes(Because multiple edges are not allowed)
You can try this Cases
Input :

Code: Select all

3

3 3
1 1 0
1 1 1
1 0 0

2 2
1 1
1 1

3 3
1 0 0
1 1 1
0 1 1
Output :

Code: Select all

No
No
No
In 1st case first column(edge) has three vertex which is not possible
In 2nd case 1st and 2nd edges have the same vertexes (1,2) and (1,2) so again No
In 3rd case same thing occurs like 2nd case.Here 2nd and 3rd edges have the same vertexes (2,3) and (2,3)

brianfry713
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Location: San Jose, CA, USA

### Re: 11550 - Demanding Dilemma

input

Code: Select all

1
4 3
1 1 1
1 0 0
0 1 0
0 0 0
output No
Check input and AC output for thousands of problems on uDebug!

uDebug
A great helper
Posts: 475
Joined: Tue Jul 24, 2012 4:23 pm

### Re: 11550 - Demanding Dilemma

Added some input to help with testing / debugging here:

http://www.udebug.com/UVa/11550
Check input and AC output for over 7,500 problems on uDebug!