# Yahoo Placement Paper

**Yahoo Placement Paper**

2) Written Test

3) Interview

**Written Test:**

All Questions are multiple types

A. 0 B. 1 C. 6 D. 7 E. 8

5. If we have a ring counter of 4 bits, with an initial state of 1000, what is the modulus of the counter?

a. 16 b.8 c.32 d.4 e. Node of the above

6. Which of the following masks can be used to zero out alternate bits of a 16 bit number?

a. 0101 b. AAAA c. FFFF d. EEEE e. BBBB

{

unsigned int r=0;

unsigned int i,j,k;

for(i=1;i<=n;i++) for(j=1;j<=i;j++) for(k=j;k<=i+j;k++) r++ return r; }

a. func(n)=summation of i*(i+1) with i varing from 1to n

b. func(n)=n*n+1 + n*n-1

c. func(n)=func(n-1)+n*n+n with func(n)=0

d. func(n)=func(n-1)+n*n+2 with func(n)=0

e. both a and c.

**Question 8:**

Which of the following statements about the datagram sent by a node in a network using IPv4 protocol is (are) true?

i. Datagrams at the source must be the size of the smallest maximum transmission unit (MTU) of alla the links on a path to the destination

ii. Datagrams may be fragmented during routing

iii. Datagrams are re-assembled at the destinations

A. I only B. II only C. III only D. I and III E. II and III

**Question 9:**

In a pipeline RISC computer all arithmetic instructions have the same CPI(Cycles per instructions), which of the following actions would improve the execution time of a tpical; program?

i. Instructions the clock cycle rate

ii. Disallowing any forwarding in the pipeline

iii. Doubling the sizes of the instruction acache and the data cache without changing the clock cycle time

A. I only B.II only C.III only D. I and II E. I and III

**Question 10:**

Let n(1), n(2), n(3)…. n(t) be positive integers. What is the minimum number N of objects to ensure that if N objects are placed into t boxes, for some I in [1,t], box I contains at least n(i) objects?

i. n(1)+ n(2)+ n(3)+….+ n(t)

ii. n(1)+ n(2)+ n(3)+….+ n(t)+t-1

iii. n(1)+ n(2)+ n(3)+….+ n(t)-t

iv. n(1)+ n(2)+ n(3)+….+ n(t)-t-1

v. n(1)+ n(2)+ n(3)+….+ n(t)-t+1

**Question 11.**

#define scanf “%s is a string”

Main(){

Printf(scanf,scanf);

}

What is the output?

A. Ccompiler error B. scanf is a string

C. %s is a string is a string D. %s is a string

**Question 12.**

#define boo(x) x/4 Main(){

Int I;

I=64/boo(4);

Printf(“%dn”,i);

}

A. Compiler time error

B. 16

C. 64

D. 20

E. Divide by Zero Error

**Question 13.**

What the following C function will do?

Unsigned int bitwise(Unsigned int x)

{

Unsigned int r=x &-x;

Unsigned int l

x+=r if(0==l) return 0; l=x &-x; l-=r;

while(0==(l&l)

{

l>>=1;

}

Return x|(l>>1);

}

A. Return the greatest integer smaller then x

B. Returns x/2

C. Returns the smallest integer greater than x with the some number of bits set

D. Returns the smallest integer greater than x with less number of bits set

E. None of the above

**Question 14.**

Int i

Void intcrement(int i)

{

I++

}

Int main()

{

For(i=0;i<10; increment(i)) { } Printf(“i=%d”,i); Return 0; } Predict the output of the above C ode A. I=10 B. I=9 C. I=11 D. Compiler Error E. None of the above

**Question 15.**

Consider the following C program

Main()

{

Int i=0;

I++;

Fork();

Printf(“d”,i);

I++;

Fork();

Printf(“d”,i);

}

What is the maximum value of the I that will be printed?

A. 0

B. 7

C. 5

D. 2

E. 10

**Question 16.**

#include

Using namespace std;

Template

Void swap( T *a, T *b){

Temp =*a;

*a=*b

*b=temp;

}

Int main(){

Char hello[]=”hello”;

Char world[]=”world”;

Swap((char *)&hello, (char **)&world);

Cout<

Consider a Binary Tee represented as a 1-indexed array(where the children of an element L are at indexes L and 2*L+1, elements at index is the root), with elements 1,2,3,4,5,6,7 in that order. If the post order traversal of the array gives ab-cd*+, the the lebel on the nodes 1,2,3,4,5,6,7 can be

A. +,-,*,a,b,c,d

B. a,-,b,+,c,*,d

C. a,b,c,d,-,*,+

D. -, a,b,+,*,c,d

E. none of the above

**Question 18.**

A hypercube is defined as follows:

A hypercube of dimension 0 has only a vertex. To construct a hypercube of N dimentions, take two N-1 dimentional hypercubes, and attach edges between corresponding nodes of each of these hypercubes. How many colors will you need to color the EDGES of an N dimentional hypercube such that no two edges of the same color share a common vertex?

A. 2

B. 2^N

C. N

D. N^2

E. Node of the above

**Question 19.**

Find the complexity function

F(n)=2F(n/2)+10n, if n>1

F(n)=1, if n=1

A. n^2

B. n(logn)^2

C. n

D. nlogn

E. None of the above

**Question 20.**

In each step of insertion sort algorithm, a new elemennt has to be inserted into an already sorted subarry. Instead of using sequential search to determine the location of new element which takes O(n) time( Which makes the overall cpmplexity O(n^2) ), We can use bunary search since the subarray is sorted, which will take O(logn) time. By using this techinue, we can reduce the complexity of insertion sort from O(n^2) to

A. O(nlogn)

B. O(n)

C. O(logn)

D. O(n^2)

E. O(1)

**Question 21.**

Cossider the following procedure: f(n)

for i=1 to n dp

j=n while j>i do

j=j-1

end while end for

Assume the above procedure are only an integer n>0; What is the time complexity in n for the procedure above:

A. O(nlogn)

B. O(n)

C. O(n^2)

D. O(N^3)

E. O(1)

**Question 22.**

A. O(1)

B. O(n)

C. O(logn)

D. O(n^2)

E. O(nlogn)

**Question 23.**

A. Merge sort

B. Insertion Sort

C. Quick Sort

D. Counting sort

E. Bubble SOrt

**Question 24.**

A. Best if A is in row-major and B is in Column Major Order.

B. Best if both are in row major

C. Best if both are in column major

D. Independent of the storage scheme.

E. None of the above

**Question 25.**

A. O(n)

B. O(log n)

C. O(logN)

D. O(loglog n)

E. O(loglogN)