# getting nzec.. plz help...

I tried to run this program for the primedistance question asked in august 13 challenge… I just visited every node and checked it’s distance from every other node… it’s giving correct answers for some test cases that I tried but on submitting it, it’s showing nzec error… help plz… here’s the code…

`````` class CLASSNAME {
static long total=0;
public void solve(int testNumber, InputReader in, OutputWriter out) {
boolean[][] tree=new boolean[n+1][n+1];
boolean[] isPrime=IntegerUtils.generatePrimalityTable(100001);
boolean[] isVis;
for(int i=1;i<n;i++){
tree[a][b]=tree[b][a]=true;
}

for(int i=1;i<=n;i++){
isVis=new boolean[n+1];
recurse(tree,isPrime,isVis,1,i);
}
//out.printLine(total);
out.printLine((total/2)/((n*(n-1))/2.0));
}
static void recurse(boolean[][] tree,boolean[] isPrime,boolean[] isVis,int sum,int level){
if(isVis[level])return;
isVis[level]=true;
//if(level>=tree[0].length)return;
for(int i=1;i<tree[0].length;i++){
if(tree[level][i]){
if(isPrime[sum] && !isVis[i]){
total++;
//System.out.println(level+" "+i+" "+sum);
}
recurse(tree,isPrime,isVis,sum+1,i);
}
}
}
}``````

``````3
1 2
2 3
``````

returns 0.3333333333333333

while for

``````3
3 2
2 1
``````

it returns 0.0, but it is the same tree…

1 Like

I changed the code where i am getting input…
for(int i=1;i<n;i++){
tree[Math.min(a,b)][Math.max(a, b)]=true;
}

``````7
1 2
2 3
3 6
3 4
4 5
6 7
``````

?

Graph is:

``````1 - 2 - 3 - 4 - 5
|
6
|
7
``````

your code returns `0.42857142857142855`, but I think it’s 10/21 = `0.4761904`

``````2: 1-3, 2-4, 2-6, 3-5, 3-7, 4-6
3: 1-6, 1-4, 2-5, 2-7
``````

it should be 12/21…isn’t it?
how does it come to 10??

I wrote all “prime paths” and there are 10 above…

you missed out 4-7 and 5-6

you are correct, but you found your problem also, the probability is 12/21 instead of 9/21…

now it’s giving nzec…
check the code…i’ve edited it in the question itself…

Please remove the tag ‘aug13’ from this. Don’t pollute the AUG13 editorial space.

editorial tag is for editorials not aug13

1 Like

@betlista- very well said…

1 Like
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