## 11063 - B2-Sequence

Moderator: Board moderators

asif_iut
New poster
Posts: 16
Joined: Mon Nov 01, 2010 8:08 am

### Re: 11063 - B2-Sequence

I found a couple of mistakes...

Second,
if(i>=2)if(Arr==(Arr[i-1]+Arr[i-2]))flg=1;

this line is wrong.
Consider the test case:

3
1 3 4

The sequence is a B2 sequence but your output shows it is not a B2 sequence.

plamplam
Experienced poster
Posts: 150
Joined: Fri May 06, 2011 11:37 am

### Re: 11063 - B2-Sequence

After taking all the numbers as input, store them in an array. Now if ar[0] < 1 it is not obviously a B2 Sequence(see the description again). Also ar[k] must be less than ar[k + 1] for it to be a B2 sequence. Also note that i <= j. So for the first sample input:
4
1 2 4 8
The sums should be calculated as: 1 + 1, 1 + 2, 1 + 4, 1 + 8, 2 + 2, 2 + 4.........8 + 8
Brute force is enough to solve this problem, so you don't need any optimization(unless you want a higher rank), there is a blank line after every test case(including the last one), and make sure to print a . at the end of each output. There ya go, you should get AC now
You tried your best and you failed miserably. The lesson is 'never try'. -Homer Simpson

BUET
New poster
Posts: 22
Joined: Sun Jun 13, 2010 8:38 am

### 11063 - B2-Sequence

for each (i,j) with i<=j ,I have saved value+value[j] in a set, not multiset. In multiset,same data can be presented more than one.

If there is no duplicate of value+value[j] for different pairs(i,j) with (i<=j).

then no. of elements in the set would be (n*(n-1))/2 + n = (n*n-n)/2

Otherwise it is not B2 sequence.

Although we have to check some other conditions such as value[0] >= 1 && value[j] > value ( for j > i)

BUET
07 Batch

shondhi
New poster
Posts: 25
Joined: Tue Oct 02, 2012 5:24 pm
Location: Chittagong
Contact:

### Why WA in UVa: 11063 - B2-Sequence?

I can't understand what's wrong in my code. Can anyone help me to fix my code? My Code is:

Code: Select all

``````#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
int cases, i, number[102], caseno = 0;
while(scanf("%d", &cases) == 1)
{
int count = 0;
for(i = 1; i <= cases; i++)
{
scanf("%d", &number[i]);
}
for(i = 1; i <= cases; i++)
{
if(number[i+1] - number[i] == number[i])
{
count = 1;
}
}
if(count == 1)
{
printf("Case #%d: It is a B2-Sequence.\n", ++caseno);
}
else
{
printf("Case #%d: It is not a B2-Sequence.\n", ++caseno);
}
if(caseno > 0)
{
printf("\n");
}
}
return 0;
}
``````

brianfry713
Guru
Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

### Re: Why WA in UVa: 11063 - B2-Sequence?

Input:

Code: Select all

``````4
1 2 3 3
4
15 16 17 18
4
-5 0 5 9
6
1 9 19 0 45 70
6
1 9 19 45 70 150
5
15 16 -1 17 18
4
2 2 2 3
4
2 2 2 2
4
1 9 18 36
5
1 9 10 18 36``````
Correct output:

Code: Select all

``````Case #1: It is not a B2-Sequence.

Case #2: It is not a B2-Sequence.

Case #3: It is not a B2-Sequence.

Case #4: It is not a B2-Sequence.

Case #5: It is a B2-Sequence.

Case #6: It is not a B2-Sequence.

Case #7: It is not a B2-Sequence.

Case #8: It is not a B2-Sequence.

Case #9: It is a B2-Sequence.

Case #10: It is not a B2-Sequence.

``````
Check input and AC output for thousands of problems on uDebug!

omarking06
New poster
Posts: 6
Joined: Fri Mar 15, 2013 1:07 am

### Re: Why WA in UVa: 11063 - B2-Sequence?

WHY WA !!?

Code: Select all

``````#include <iostream>
using namespace std;

int main ()
{
int t=1,num[99],sum[10000],s,c;
bool res;
while (cin>>s)
{
res=true;
for (int j=0;j<s;j++)
cin>>num[j];

for (int k=0;k<s-1;k++)
if (num[k]<1 || num[k]>=num[k+1] )
{
res=false;
break;
}

c=0;

for (int i=0;i<s;i++)
for (int l=i;l<s;l++)
{
sum[c]= num[i]+num[l];
c++;
}

for (int x=0;x<s;x++)
for (int y=0;y<s;y++)
if (sum[x]==sum[y] && y!=x) res=false;
else continue;

if (res==true)
cout<<"Case #"<<t<<": It is a B2-Sequence."<<endl;
else if (res==false)
cout<<"Case #"<<t<<": It is not a B2-Sequence."<<endl;
cout<<endl;
t++;

}
return 0;
}``````

omarking06
New poster
Posts: 6
Joined: Fri Mar 15, 2013 1:07 am

### Re: 11063 - B2-Sequence

WHY WA !!?

Code: Select all

``````#include <iostream>
using namespace std;

int main ()
{
int t=1,num[99],sum[10000],s,c;
bool res;
while (cin>>s)
{
res=true;
for (int j=0;j<s;j++)
cin>>num[j];

for (int k=0;k<s-1;k++)
if (num[k]<1 || num[k]>=num[k+1] )
{
res=false;
break;
}

c=0;

for (int i=0;i<s;i++)
for (int l=i;l<s;l++)
{
sum[c]= num[i]+num[l];
c++;
}

for (int x=0;x<s;x++)
for (int y=0;y<s;y++)
if (sum[x]==sum[y] && y!=x) res=false;
else continue;

if (res==true)
cout<<"Case #"<<t<<": It is a B2-Sequence."<<endl;
else if (res==false)
cout<<"Case #"<<t<<": It is not a B2-Sequence."<<endl;
cout<<endl;
t++;

}
return 0;
}``````

brianfry713
Guru
Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

### Re: 11063 - B2-Sequence

Don't double post.
Check input and AC output for thousands of problems on uDebug!

brianfry713
Guru
Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

### Re: Why WA in UVa: 11063 - B2-Sequence?

Doesn't match the sample I/O.
Check input and AC output for thousands of problems on uDebug!

Examiner
New poster
Posts: 27
Joined: Thu Feb 19, 2004 1:19 pm

### Re: 11063 - B2-Sequence

Try this:

Code: Select all

``````3
1 3 5``````

terry646623
New poster
Posts: 8
Joined: Fri Jan 17, 2014 3:35 pm

### Re: 11063 - B2-Sequence

why do I get wrong answer

Code: Select all

``````Yeah...This is a AC code. I just don't know why the system told that this is wrong answer before...
``````
Last edited by terry646623 on Sat Mar 29, 2014 6:12 pm, edited 1 time in total.

brianfry713
Guru
Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

### Re: 11063 - B2-Sequence

That is AC code
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: 11063 - B2-Sequence

Check input and AC output for over 7,500 problems on uDebug!

SR7
New poster
Posts: 4
Joined: Fri Aug 14, 2015 6:36 pm

### Re: WA!!!

plz help...

I've tried with a lot of i/o....but couldn't fix what's wrong with this==>

Code: Select all

``````
#include<stdio.h>
int main()
{
int i,j,k,x,y,z,n,tc=0,ara[101],f;
long sum[100000];
while(scanf("%d",&n)==1){
tc++;
for(i=0; i<n; i++){
scanf("%d", &ara[i]);
}
f=0;
for(i=1; i<n; i++){
if(ara[i]<=ara[i-1] || ara[i-1]<1){
f=1;
break;
}
}
if(f==1){
printf("Case #%d: It is not a B2-Sequence.\n",tc);
continue;
}
k=0;
for(i=0; i<n; i++){
for(j=n-1;j>=i;j--){
sum[k] = ara[i]+ara[j];
k++;
}
}
z=0;
for(x=0; x<k; x++){
for(y=k-1; y>x; y--){
if(sum[x]==sum[y]){
z=1;
break;
}
}
if(z==1) break;
}
if(z==0) printf("Case #%d: It is a B2-Sequence.\n",tc);
else printf("Case #%d: It is not a B2-Sequence.\n",tc);
printf("\n");
}
return 0;
}``````
Last edited by brianfry713 on Wed Aug 19, 2015 8:52 pm, edited 1 time in total.