Yahoo Placement Papers

1. Yahoo Interview questions
􀀹 How to call a C++ function which is compiled with C++ compiler in C code?
􀀹 When you deliver your C++ headers and C++ library of a class (what all can you
change in the class so that application using your class does not need to recompile
the code)
􀀹 How do you initialize a static member of a class with return value of some function?
􀀹 How can one application use same API provided by different vendors at the same
time?
􀀹 If you are given the name of the function at run time how will you invoke the
function?
􀀹 When will you use shell script/Perl ahead of C/C++?
􀀹 How does yahoo handles billions of requests, does it create a thread per request or
a process?
􀀹 How does HTTP works?
􀀹 How to count number of unique music titles downloaded from a log file which
contains an entry of all music title downloaded?
􀀹 What is the difference between COM and CORBA?
􀀹 What is web service?
􀀹 Design classes for the following problem. (C++)
A Customer Can have multiple bank accounts A Bank account can be owned by
multiple customers When customer logs in he sees list of account, on clicking on an
account he sees list of transactions.
2. YAHOO PLACEMENT SAMPLE WRITTEN PAPER
􀀹 In a village in each family they give birth to children till they
get a boy. IF girl child they try again. What is the ratio of boys to
girls.
􀀹 2n+1 numbers in a list except for 1 num all had duplicates, how to
find duplicate in O(n)
􀀹 In 1000 wine bottles stack 10 are poisoned given 10 rats what is
the minimum number of tries to find the poisoned one. Rat dies once it
licks the poisoned wine.
􀀹 Write 1,3,6,4 using +,‐,*,/ to get 24 (no repeat of numbers)
􀀹 Which is the DS used in dictionary mode in mobile (t9)
􀀹 Which is DS used for chess program...to predict move each and every
time..
􀀹 There are $1070 dollars how to split them into bags such that asked
for any denomination from $1 to $1070 , u must b able to give without
opening bag
􀀹 First fit issues...
􀀹 Algorithm to partition set of numbers into two s.t. diff bw their
sum is min and they hav equal num of elements
􀀹 Prog: given Numerator & Denominator.... print 0.3333333333 as .(3)
0.123123 as .(123)
􀀹 What is the output of the following code?
x=0;y=1;
for( j=1;j<4;j++){
x=x+j;
y*=j;
}
􀀹 There is a 200 miles long tunnel. one train enters the tunnel at a speed of 200mph
while the other trains enter the tunnel in the opposite direction at a speed of 1000
mph. A bee travels at a speed of 1500 mph enters the tunnel goes to and back until
it reaches the train. What is the distance covered by the bee when the two train
collides (the bee survives)
􀀹 List the two advantages of views.
􀀹 Which layer is encryption and decryption done
􀀹 What are the various modes used to send data over the network
􀀹 Write a query to display the name of the students whose total marks is divisible by
25(total marks may be 175,200,150 ….)
􀀹 P(S1)
a++;
P(S2)
v++;
V(S2)
V(S1)
P‐wait, V‐signal, S1 and S2 are semaphores. Consider two threads running. Is there a
deadlock .If yes in which situation does the deadlock occur.
􀀹 How do you find the port number of the remote host?
􀀹 (Date; who)>logfile
Date; who>logfile
What is the difference between the two statements.
􀀹 How do you find the machine MAC address
􀀹 Write the set operators that are used for select.
􀀹 Write a single command to find and delete all the files that are older than 1
day(modification time)
􀀹 A is a 3*4 matrix and B is 4*5 matrix. What is the number of additions and
multiplications performed to obtain the resultant matrix
􀀹 What is the output
#!/bin/perl
kill –0 pid
􀀹 #!/bin/perl
echo $_
􀀹 #!/bin/perl
kill $$
echo “hello world”
􀀹 List different schema/database objects
􀀹 Randomization is good for which algorithm(quick sort, heap sort, selection sort,
hashed table, ….)
􀀹 Descride the language in the following regular expression (a*a) b+b
􀀹 In an I‐node what is not there (file type, file name, size, owner)
􀀹 If the probability of work done by three persons are 1/3, 2/5, 5/12. Then what is the
probability that the work is completed.
􀀹 Given Id, author, creation time, size, links, web page, description
Bring it in 2nd normal form
􀀹 Consider a heap containing numbers 10, 20, 30, 40, 80, 60, 70 such that numbers
are in ascending order from the leaf to the root. If 25 is to be inserted what is the
position.(A[1], A[2], A[3], A[4])
􀀹 #!/bin/perl
var=///
aaaa
echo ‘$var’
􀀹 Krishna tosses a one‐rupee coin and a rupee coin. He announces that one is head.
But the result is not announced. What is the probability that the other coin is head?
􀀹 In database sort the student id and the course id for each student. Which is the best
possible solution.
‐Sort the student id using a stable algorithm and then sort the course id using
unstable algorithm
‐Sort the student id using a unstable algorithm and then sort the course id using
stable algorithm
‐Sort the course id using a stable algorithm and then sort the student id using
unstable algorithm
‐Sort the course id using a unstable algorithm and then sort the student id using
unstable algorithm