# WA in CHEFDAG(SOLVED)

Problem link : CodeChef: Practical coding for everyone
My Solution : https://www.codechef.com/viewsolution/30307347
Correct solution (of @vd_patel ) : https://www.codechef.com/viewsolution/30378162
I have checked my code and vd_patel’s code on like 15-16 different input and everytime both output are same but still i am getting WA in all subtask.
so, can you please tell me where am I going wrong or any testcase where my output is wrong.

If anyone would require a little explanation of my approach then this is it :

First of all i created a list where list[i] contained all the nodes except i which means that if n=5 then list[1] will contain 2,3,4,5 and list[2] will contain 1,3,4,5 and so on.Now for each of the next k lines which is a permutation of 1 to N , I took the input in array a and removed a[j] from the list of a[i] for all j<i and I did this for all i<=n.Let’s take an example;
Suppose the permutation is : 3 2 4 1 5
Then i removed 3 from list[2]
removed 3 and 2 from list[4]
removed 3,2 and 4 from list[1]
and removed 3,2,4 and 1 from list[5]
After doing this for each one of the k lines , i iterated over all the list and counted the occurence of each element in the list.
For eg:if list[1]=5
list[2]=4,5
list[3]=2,4,1,5
list[4]=1,5
list[5]=empty
then c[1]=2(in list[3] and list[4])
c[2]=1
c[3]=0
c[4]=2
c[5]=4
then created an array flag initialised to 0
Now for each i , the answer would be the node present in list[i] with minimum count && flag[node]==0 and if the list is empty or flag of all the elements is 1 then answer will be 0 and will set the flag[ans]=1

Bit of spamming got me this test case

``````1
20 2
18 9 8 7 17 20 4 3 1 12 2 13 10 14 5 16 11 15 19 6
20 3 4 10 19 7 11 12 8 18 1 6 2 15 14 5 9 17 16 13
``````

``````7
2 14 10 12 16 0 17 1 13 19 6 5 0 0 0 0 0 9 0 3
``````

``````5
2 14 12 10 16 0 11 1 17 19 15 6 0 5 0 0 13 9 0 3
``````
2 Likes

Thanks
@everule1

1 Like

@everule1 Can you please help me as well.I cant figure out what is wrong with my code for CHEF DAG as it passes through every test cases which i could thought of.
Solution Link:-CodeChef: Practical coding for everyone
Your help will be highly appreciated.

MY code gives correct output for the test case given by you.Still its getting WA verdict.
My solution is CodeChef: Practical coding for everyone.
Kindly help me with a test case

Luckily your code failed on a small test case

``````1
5 3
1 4 5 2 3
1 3 4 5 2
4 1 5 2 3
``````

``````3
5 0 0 0 2
``````

correct output:

``````2
3 0 0 5 2
``````
2 Likes

Thanks a lot!

``````1
15 3
7 10 6 15 8 2 5 4 11 3 14 1 13 12 9
13 11 9 7 15 14 8 3 6 2 1 4 5 12 10
6 14 8 15 9 12 7 1 11 2 4 3 10 5 13
``````

``````9
0 4 0 0 0 2 5 12 0 0 3 0 0 1 0
``````

Correct output:

``````8
0 4 0 0 0 1 10 5 0 0 3 0 0 12 2
``````

Thanks a lot Sir

is this a valid solution?
5
2 14 19 10 16 0 12 1 17 11 6 15 0 5 0 0 13 9 6 4

6 is pointed by two nodes

Yes.