Answer / hitesh viradiya

m = 1 2 3 4 5 6 7 8
n=1 1
2 1 1
3 2 2 1
4 5 5 3 1
5 14 14 9 4 1
6 42 42 28 14 5 1
7 132 132 90 48 20 6 1
8 429 429 297 165 75 27 7 1

(2n)!/[(n+1)!n!]

Answer / kathir

There are 2 pointers available for each node.
So we can have 2*n pointers totally.

Total no. of edges = n-1

So, Null pointers = n+1.

We need to choose (n-1) pointers from 2n pointers.

So the combination results in (2n)C(n-1).

We can have n distinct roots possible.

So, answer will be (2n) C (n-1) / n.

which leads to,

{2n C n}/{n+1}. ( Unlabelled )


Labelled Structured tree will be,

{2n C n}/{n+1} * {n!}

Answer / durga prasad sahoo

No. of labeled binary tree :

n^(n-2)

No. unlabeled binary tree :

(2n)!/[(n+1)!.n!] (this is known as catlon number)

Answer / atul barve

No. of labeled binary tree :

{(2n)!/[(n+1)!.n!]}*n!

No. unlabeled binary tree :

(2n)!/[(n+1)!.n!] (this is known as catlon number)

Answer / neha shah

(2n)!/(n+1)!*n!

Answer / fawad ghafoor

The number of different trees with 8 nodes is 248
2^n - n

Answer / ajeet

int countTrees(int num)
{
if(num<=1)
return 1;
else
{
int root,left,right,sum=0;
for(root=1;root<=num;root++)
{
left=countTrees(root-1);
right=countTrees(num-root);
sum+=left*right;
}
return sum;
}
}

Answer / munyazikwiye pierre celestin

(2n)!/[(n+1)!*n!]

Answer / sayandip ghosh

The max number of binary trees that can be formed from n
nodes is given by the Catlan Number C(n).

C(n) = (2n)! / (n+1)!*n! for n>=0.

int findNoTree(int low ,int high)
{
int sum=0;
if(low<=high)
{
for(int k=low;k<=high;k++)
{
if(k==low)
sum+=findNoTree(low+1,high);
else
{
if(k==high)
sum+=findNoTree(low,high-1);
else

sum=sum+findNoTree(low,k-1)*findNoTree(k+1,high);
}
}

return sum;
}
return 1;
}

Answer / sachin

(2n)!/(n+1)!

what will be the position of the file marker? a: fseek(ptr,0,SEEK_SET); b: fseek(ptr,0,SEEK_CUR);

2 Answers  

#include<stdio.h> main() { int a[2][2][2] = { {10,2,3,4}, {5,6,7,8} }; int *p,*q; p=&a[2][2][2]; *q=***a; printf("%d..%d",*p,*q); }

1 Answers  

main(int argc, char *argv[]) { (main && argc) ? main(argc-1, NULL) : return 0; } a. Runtime error. b. Compile error. Illegal syntax c. Gets into Infinite loop d. None of the above

4 Answers   HCL, LG,

int a = 10 + 10 .... ,... A = A * A What would be the value of A? The answer is 120!! Could anyone explain this to me.

2 Answers   Bosch, eInfochips, HCL, IHCL,

#include<stdio.h> main() { int i=1,j=2; switch(i) { case 1: printf("GOOD"); break; case j: printf("BAD"); break; } }

1 Answers  

Is it possible to print a name without using commas, double quotes,semi-colons?

7 Answers  

write a c-program to find gcd using recursive functions

5 Answers   HTC, Infotech,

#define square(x) x*x main() { int i; i = 64/square(4); printf("%d",i); }

4 Answers   Google, HCL, Quick Heal, WTF,

void main() { int i=5; printf("%d",i+++++i); }

3 Answers  

main() { char a[4]="HELL"; printf("%s",a); }

3 Answers   Wipro,

#include<stdio.h> main() { const int i=4; float j; j = ++i; printf("%d %f", i,++j); }

1 Answers  

prog. to produce 1 2 3 4 5 6 7 8 9 10

4 Answers   TCS,