AMCAT Computer Science Questions with Answers - 2

AMCAT Computer Programming Previous Years Question answers with Solutions 2


Ques31. Shalini wants to program to print the largest number out of three inputted
numbers. She writes the following program:
int number1, number 2, number3, temp;
input number1, number2, number3;
if (number1>number2)
temp = number1
else
temp = number2
end if
if (??) // Statement 1
temp = number3
end if
print temp
Fill in the ?? in Statement 1
Op 1: number3 > number2
Op 2: number3 > temp
Op 3: number3 < temp
Op 4: number3 > number1
Op 5:
Correct Op : 2

Ques32. Rohit writes the following program which inputs a number and prints "Double
digit" if the number is composed of two digits and "Not a double digit" if it is not.
int number;
if (number>10 AND number < 100)
print "Double digit"
else
print "Not a double digit"
end if
Rohit tries the following inputs: 5 and 66. The program works fine. He asks his
brother Ravi to try the program. When Ravi enters a number, the program doesn't
work correctly. What did Ravi enter?
Op 1: 8
Op 2: 100
Op 3: 99
Op 4: 10
Op 5:
Correct Op : 4

Ques33. Rohan writes the following program which inputs a number and prints "Triple
digit" if the number is composed of three digits and "Not triple digit" if it is not.
int number;
if (number>99)
print "Triple digit"
else
print "Not triple digit"
end if
Rohan tries the following inputs: 25 and 566. The program works fine. He asks his
brother Ravi to try the program. When Ravi enters a number, the program doesn't
work correctly. What did Ravi enter?
Op 1: 99
Op 2: 100
Op 3: 0
Op 4: 1000
Op 5:
Correct Op : 4

Ques34. Abhinav wants to find the largest number in a given list of 20 numbers. Which
of the following is an efficient approach to do this?
Op 1: Use bubble sort to sort the list in descending order and then print the first
number of the series.
Op 2: Use selection sort to sort the list in descending order and then print the first
number of the series.
Op 3: Implement one iteration of selection sort for descending order and print the
first number in the series.
Op 4: None of these
Op 5:
Correct Op : 3

Ques35. Lavanya wants to find the smallest number out of 26 inputted numbers. How
many minimum comparisons he has to make?
Op 1: 25
Op 2: 13
Op 3: 26
Op 4: 52
Op 5:
Correct Op : 1

Ques36. A company offers commission for selling it products to its salesperson. The
commission rate is Rs. 5 per product. However if the salesperson sells more than 200
items, he gets a commission of Rs. 10 on all items he sold after the first 200. Kanu
writes a program to calculate the commission for the salesperson:
integer numberProducts, commission
input numberProducts
if ( numberProducts > 200 )
-- MISSING STATEMENT --
else
commission = numberProducts * 5
end if
print commission
Fill in the missing statement.
Op 1: commission = (numberProducts - 200) * 10
Op 2: commission = 200 * 5 + (numberProducts - 200) * 10
Op 3: commission = numberProducts * 10
Op 4: None of these
Op 5:
Correct Op : 2

Ques37. Vikram wants to write a program which checks whether the inputted number
is divisible by any of the first 6 natural numbers (excluding 1). He writes the following
efficient code for it.
int number, n = 2, isdivisible=0
input number
while ( n <=6) // Statement 1
{
if ( remainder (number, n) == 0)
isdivisible = 1
end
n = n+1 // Statement 2
}
if (isdivisible equals 1)
print "It is divisible"
else
print "It is not divisible"
end
Vikram takes the program to Hari. Hari tells Vikram that though the code is correct, it
can be made more efficient. Hari modifies a single statement and makes the code
more efficient. Which statement does he modify and how?
Op 1: Statement 1 is changed to:
while (n <=6 AND isdivisible=0)
Op 2: Statement 1 is changed to:
while (n <=6 OR isdivisible=0)
Op 3: Statement 1 is changed to:
while (isdivisible=0)
Op 4: Statement 2 is changed to:
n = n + 2
Op 5:
Correct Op : 1

Ques38. Rajiv wants to make a program which inputs two numbers: a and b (a>b)
and computes the number of terms between a and b (including a and b). What will
be code statement to do this:
Op 1: a - b
Op 2: a - b + 1
Op 3: a + b
Op 4: a - b - 1
Op 5:
Correct Op : 2

Ques39. I have a problem to solve which takes as input a number n. The problem has a
property that given the solution for (n-1), I can easily solve the problem for n. Which
programming technique will I use to solve such a problem?
Op 1: Iteration
Op 2: Decision-making
Op 3: Object Oriented Programming
Op 4: Recursion
Op 5:
Correct Op : 4

Ques40. What is the output of the following code statements? The compiler saves the
first integer at the memory location 4062. Integer is one byte long.
integer a
pointer b
a = 20
b = &a
print *b
Op 1: 4062
Op 2: 4063
Op 3: 20
Op 4: 10
Op 5:
Correct Op : 3

Ques41. What is the output of the following code statements? The compiler saves the
first integer at the memory location 4165 and the rest at consecutive memory spaces
in order of declaration. Integer is one byte long.
integer a, b
pointer c, d
a = 30
c = &a
b = *c
a = a + 10
print b
Op 1: 30
Op 2: 4165
Op 3: 40
Op 4: 4166
Op 5:
Correct Op : 1

Ques42. What is the output of the following code statements? The compiler saves the
first integer at the memory location 4165 and the rest at consecutive memory spaces
in order of declaration. Integer is one byte long.
integer a
pointer c, d
a = 30
c = &a
d = c
a = a + 10
print *c
Op 1: 30
Op 2: 4165
Op 3: 40
Op 4: 4166
Op 5:
Correct Op : 3

Ques43. What is space complexity of a program?
Op 1: Amount of hard-disk space required to store the program
Op 2: Amount of hard-disk space required to compile the program
Op 3: Amount of memory required by the program to run
Op 4: Amount of memory required for the program to compile
Op 5:
Correct Op : 3

Ques44. The memory space needed by an algorithm has a fixed part independent of
the problem instance solved and a variable part which changes according to the
problem instance solved. In general, which of these two is of prime concern to an
algorithm designer?
Op 1: Fixed part
Op 2: Variable Part
Op 3: Product of fixed part and variable part
Op 4: None of these
Op 5:
Correct Op : 2

Ques45. While calculating time complexity of an algorithm, the designer concerns
himself/herself primarily with the run time and not the compile time. Why?
Op 1: Run time is always more than compile time.
Op 2: Compile time is always more than run time.
Op 3: Compile time is a function of run time.
Op 4: A program needs to be compiled once but can be run several times.
Op 5:
Correct Op : 4

Ques46. Pankaj and Mythili were both asked to write the code to evaluate the
following expression:
a - b + c/(a-b) + (a-b)2
Pankaj writes the following code statements (Code A):
print (a-b) + c/(a-b) + (a-b)*(a-b)
Mythili writes the following code statements (Code B):
d = (a-b)
print d + c/d + d*d
If the time taken to load a value in a variable, for addition, multiplication or division
between two operands is same, which of the following is true?
Op 1: Code A uses lesser memory and is slower than Code B
Op 2: Code A uses lesser memory and is faster than Code B
Op 3: Code A uses more memory and is faster than Code B
Op 4: Code A uses more memory and is slower than Code B
Op 5:
Correct Op : 1

Ques47. Vrinda writes an efficient program to sum two square diagonal matrices
(matrices with elements only on diagonal). The size of each matrix is nXn. What is the
time complexity of Vrinda's algorithm?
Op 1: &theta(n^2)
Op 2: &theta(n)
Op 3: &theta(n*log(n))
Op 4: None of these
Op 5:
Correct Op : 2

Ques48. Tarang writes an efficient program to add two upper triangular 10X10 matrices
(elements on diagonal retained). How many total additions will his program make?
Op 1: 100
Op 2: 55
Op 3: 25
Op 4: 10
Op 5:
Correct Op : 2

Ques49. Ravi and Rupali are asked to write a program to sum the rows of a 2X2
matrices stored in the array A.
Ravi writes the following code (Code A):
for n = 0 to 1
sumRow1[n] = A[n][1] + A[n][2]
end
Rupali writes the following code (Code B):
sumRow1[0] = A[0][1] + A[0][2]
sumRow1[1] = A[1][1] + A[1][2]
Comment upon these codes (Assume no loop-unrolling done by compiler):
Op 1: Code A will execute faster than Code B.
Op 2: Code B will execute faster than Code A
Op 3: Code A is logically incorrect.
Op 4: Code B is logically incorrect.
Op 5:
Correct Op : 2

Ques50. There is an array of size n initialized with 0. Akanksha has to write a code
which inserts the value 3k at position 3k in the array, where k=0,1…(till possible).
Akanksha writes an efficient code to do so. What is the time complexity of her code?
Op 1: &theta(n^2)
Op 2: &theta(n)
Op 3: &theta(log3(n))
Op 4: &theta(3n
)
Op 5:
Correct Op : 3

Ques51. There are two matrices A and B of size nXn. The data in both these matrices
resides only at positions where both the indices are a perfect square. Rest all
positions have 0 as the data. Manuj has available a third matrix initialized with 0's at
all positions. He writes an efficient code to put the sum of A and B in C. What is the
time complexity of Manuj's program?
Op 1: &theta(n^2)
Op 2: &theta(n)
Op 3: &theta(n1/2)
Op 4: &theta(log(n))
Op 5:
Correct Op : 2

Ques52. Ravi has to add an strictly upper triangular (no elements at diagonal) and a
strictly lower triangular square matrix (no elements at diagonal) and put the result in
a third matrix. What is the time complexity of Ravi's algorithm? Assume that storing
a value in a memory space takes negligible time, while each addition between values
takes the dominating amount of time.
Op 1: &theta(n^2)
Op 2: &theta(n)
Op 3: &theta(1)
Op 4: None of these
Op 5:
Correct Op : 3

Ques53. We have two 100X3 (rowsXcolumn) matrices containing mid-term exam marks
and end-term exam marks of 100 students. Each row refers to a particular student,
while columns refer to marks in English, Social Sciences and Maths. The end-term
and mid-term marks of each student in each subject have to be added to get his total
score in each subject, to be put in a third matrix (100X3). Parinidhi writes a code
(Code A), where the outer loop iterates over the rows, while the inner loop iterates
over the columns. Shashi writes a code (Code B), where the outer loop iterates over
the columns, while the inner loop iterates over rows. Which of the following is true
with regard to their code ignoring any caching or memory storage effects?
Op 1: Code A is faster than Code B
Op 2: Code B is faster than Code A
Op 3: Code A and Code B will run in the same amount of time
Op 4: The comparison between the speed of the codes cannot be made.
Op 5:
Correct Op : 2

Ques54. A code takes the following code steps (equivalently time unit) to execute:
5*n3 + 6*n2 + 1. Which of the following is not true about the time complexity of the
program?
Op 1: It has a time complexity of O(n3
)
Op 2: It has a time complexity of O(n4
)
Op 3: It has a time complexity of O(n2
)
Op 4: It has a time complexity of &theta(n3
)
Op 5:
Correct Op : 3

Ques55. We have two programs. We know that the first has a time complexity O(n2
),
while the second has a complexity &omega(n2
). For sufficiently large n, which of the
following cannot be true?
Op 1: Both codes have same complexity
Op 2: The first code has higher time complexity than the second
Op 3: The second code has lower time complexity than the first code.
Op 4: Both codes are the same.
Op 5:
Correct Op : 2

Ques56. The time complexity of code A is &theta(n), while for Code B it is
&theta(log(n)). Which of the following is true for sufficiently large n?
Op 1: Both code have the same time complexity
Op 2: Code A has higher time complexity
Op 3: Code B has higher time complexity
Op 4: No comparison can be made between the time complexity of the two codes.
Op 5:
Correct Op : 2

Ques57. Rajini is given an efficient code for summing two nXn matrices and putting the
result in a third matrix. She is asked to find it's time complexity. She realizes that the
number of iterations required is more than n. What can she claim with regard to the
complexity of the code?
Op 1: It is O(n)
Op 2: It is O(n2
)
Op 3: It is &theta(n)
Op 4: It is &omega(n)
Op 5:
Correct Op : 4

Ques58. Gautam is given two codes, A and B, to solve a problem, which have
complexity &theta(n) and &theta(n2
) respectively. His client wants to solve a problem
of size k, which Gautam does not know. Which code will Gautam deliver to the client,
so that the execution is faster?
Op 1: Code A
Op 2: Code B
Op 3: Gautam cannot determine
Op 4: Both codes have the same execution time, so deliver any.
Op 5:
Correct Op : 3

Ques59. Surbhi is given two codes, A and B, to solve a problem, which have complexity
O(n3
) and &omega(n4
) respectively. Her client wants to solve a problem of size k,
which is sufficiently large. Which code will Surbhi deliver to the client, so that the
execution is faster?
Op 1: Code A
Op 2: Code B
Op 3: Surbhi cannot determine
Op 4: Both codes have the same execution time, so deliver any.
Op 5:
Correct Op : 1

Ques60. Vibhu is given two codes, A and B, to solve a problem, which have complexity
O(n4
) and &omega(n3
) respectively. Her client wants to solve a problem of size k,
which is sufficiently large. Which code will Gautam deliver to the client, so that the
execution is faster?
Op 1: Code A
Op 2: Code B
Op 3: Vibhu cannot determine
Op 4: Both codes have the same execution time, so deliver any.
Op 5:
Correct Op : 3

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