Description
Problem 5.1 Triangle chars (1 point)
Language: C
Write a function that takes two arguments: an integer n and a character ch. The function should
print the character ch in a triangle form as below.
Write a simple program that reads the appropriate variables and prints the result to screen by
calling the function.
You can safely assume that the input will be valid.
Your solution has to satisfy the requirements from the problem description and has to pass the
following testcase and potentially other testcases which are uploaded. All characters are relevant
for passing testcases including newlines and spaces.
Testcase 5.1: input
4
$
Testcase 5.1: output
$$$$
$$$
$$
$
Problem 5.2 Divide with constant data (1 point)
Language: C
Write a function void divby5(float arr[], int size) that divides by 5 all elements of
an array. Your program should print in the main() function the elements of the array before and
after the division. Test your program with an array that contains the following values:
5.5, 6.5, 7.75, 8.0, 9.6, 10.36.
Your solution has to satisfy the requirements from the problem description and has to pass the
following testcase and potentially other testcases which are uploaded. All characters are relevant
for passing testcases including newlines and spaces.
Testcase 5.2: input Testcase 5.2: output
Before:
5.500 6.500 7.750 8.000 9.600 10.360
After:
1.100 1.300 1.550 1.600 1.9206 2.072
Problem 5.3 Determine lowercase characters (1 point)
Language: C
Write a function int count lower(char* str) that counts the number of lowercase characters within in a string. Then write a program where you repeatedly read a string and determine
and print the number of lowercase characters in that string. If you provide an empty string (the
string will just contain ’\n’), then the program should stop its execution. You must use a pointer
to walk through the string.
You can assume that the string will be not longer than 50 characters and will be valid.
Problem 5.4 Divide with input data (1 point)
Due by Monday, October 11th, 23:00 Graded manually
Language: C
Modify your solution for Divide I such that you first read an integer n, and then elements of an
array with n components. Therefore you will need to dynamically allocate your array. Then
divide by 5 the elements using the divby5() function and print the result from the main()
function. Do not forget to release the allocated memory when not needed anymore.
You can safely assume that the input will be valid.
Problem 5.5 Computing the scalar product of two vectors (1 point)
Due by Monday, October 11th, 23:00 Graded automatically with testcases only
Language: C
Write a program that reads a number n, and then two vectors v and w of real numbers (of type
double) with n components. Write a function that computes the scalar product of these two
vectors. The scalar product is defined as:
v · w =
Xn
i=1
vi · wi
Use the function to compute the scalar product of the two vectors you read. From the main()
function print the value of the scalar product on the screen. Additionally write functions for
determining and printing on the screen the smallest and largest components of the vector v, and
the position in the vector where they occur.
You can safely assume that the input will be valid.
Your solution has to satisfy the requirements from the problem description and has to pass the
following testcase and potentially other testcases which are uploaded. All characters are relevant
for passing testcases including newlines and spaces.
Testcase 5.5: input
3
1.1
2.5
3.0
1.0
1.0
1.0
Testcase 5.5: output
Scalar product=6.600000
The smallest = 1.100000
Position of smallest = 0
The largest = 3.000000
Position of largest = 2
The smallest = 1.000000
Position of smallest = 0
The largest = 1.000000
Position of largest = 0
Problem 5.6 Pointer arithmetic (2 points)
Due by Monday, October 11th, 23:00 Graded manually
Language: C
Write a program that counts the number of elements in an array until encountering the first
negative value without the usage of any integer counter variables (except for the loop for reading
the elements of the array), but with the usage of pointers and pointer arithmetic.
Your program should read an int for the length of the array and an array of floats (containing
at least one negative value) from the standard input. The number of non-negative values before
the first negative value should be printed on the standard output.
You can assume that the input will be valid and the array will always contain at least one negative
value. To pass the testcases your output has to be identical with the provided ones.
Testcase 5.6: input
5
1.2
3.4
-5.86
4
5.45
Testcase 5.6: output
Before the first negative value: 2 elements
Problem 5.7 Concatenating two strings (1 point)
Language: C
Write a program to concatenate two strings (with the length of at most 100 characters) putting
the result in a dynamically allocated array of chars with exact size.
Your program should read from the standard input two strings which may be statically allocated.
The dynamically allocated string containing the concatenation result of the two strings should be
printed on the standard output.
You can assume that the input will be valid. To pass the testcases your output has to be identical
with the provided ones.
Testcase 5.7: input
one
two
Testcase 5.7: output
Result of concatenation: onetwo
Problem 5.8 Dynamically allocated matrix multiplication (2 points)
Language: C
Write a program that computes the multiplication of two dynamically allocated matrices.
Your program should dynamically allocate the memory for the three matrices (two input matrices
and the result matrix). You should write functions for reading a matrix from the standard input,
printing a matrix to the standard output, and finally a function for computing the multiplication
of two matrices. At the end, do not forget to deallocate the memory used by the three matrices.
The product of two matrices A and B of dimensions n × m and m × p can be calculated as:
Cik =
Xm
j=1
Aij · Bjk, with i = 1, . . . , n and k = 1, . . . , p.
Your program should read three integers (the dimensions n, m and p) and the elements of two integer matrices from the standard input. The result of the matrix multiplication should be printed
on the standard output.
You can assume that the input will be valid. To pass the testcases your output has to be identical
with the provided ones.
Testcase 5.8: input
2
2
2
1
2
3
4
1
0
0
1
Testcase 5.8: output
Matrix A:
1 2
3 4
Matrix B:
1 0
0 1
The multiplication result AxB:
1 2
3 4
Problem 5.9 Printing dynamically allocated 3D-array sections (3 points)
Language: C
Write a program that dynamically allocates memory for a 3D-array of integers and prints the 2Dsections parallel to the “XOY axis” (considering the array dimensions row-dimension, columndimension and depth-dimension similar to the geometrical X, Y and Z dimensions) of a 3Darray.
Your program should read three integer values corresponding to the dimensions of a 3D-array
(in the order of rows, columns, depth) and should dynamically allocate the memory for this 3Darray. You should write functions for reading the elements of the 3D-array from standard input
(first iterating through rows, then columns and then the depth) and finally a function for printing
the 2D-sections of the 3D-array which are parallel to the “XOY axis”. Do not forget about the
allocation and deallocation of the memory.
You can assume that the input will be valid. To pass the testcases your output has to be identical
with the provided ones.
Testcase 5.9: input
2
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Testcase 5.9: output
Section 1:
1 1
1 1
Section 2:
2 2
2 2
Section 3:
3 3
3 3
Problem 5.10 Print numbers counting down (1 point)
Due by Monday, October 11th, 23:00 Graded manually
Language: C
Write a program which reads a positive integer n from the keyboard. Then write and call a
recursive function for printing the numbers n, n − 1, . . . , 1.
You can safely assume that the input will be valid.
Problem 5.11 Determine if a number prime (1 point)
Due by Monday, October 11th, 23:00 Graded automatically with testcases only
Language: C
Write a program which reads a positive integer x. Then write a recursive function for determining
if x is a prime number or not. The function should return 1 if the number is prime and 0 if not.
Print a corresponding message from the main() function.
You can safely assume that the input will be valid.
Your solution has to satisfy the requirements from the problem description and has to pass the
following testcase and potentially other testcases which are uploaded. All characters are relevant
for passing testcases including newlines and spaces.
Testcase 5.11: input
26
Testcase 5.11: output
26 is not prime
How to submit your solutions
• Your source code should be properly indented and compile with gcc or g++ depending on the problem without any errors or warnings (You can use gcc -Wall -o program program.c or g++
-Wall -o program program.cpp). Insert suitable comments (not on every line . . . ) to explain
what your program does.
• Name the programs according to the suggested filenames (they should match the description of the
problem) in Grader.
Each program must include a comment on the top like the following:
/*
CH-230-A
a5 p1.[c or cpp or h]
Firstname Lastname
myemail@jacobs-university.de
*/
• You have to submit your solutions via Grader at
https://grader.eecs.jacobs-university.de.
If there are problems (but only then) you can submit the programs by sending mail to
k.lipskoch@jacobs-university.de with a subject line that begins with CH-230-A.
It is important that you do begin your subject with the coursenumber, otherwise I might have
problems to identify your submission.
• Note, that after the deadline it will not be possible to submit any solutions. It is useless to send late
solutions by mail, because they will not be accepted.
This assignment is due by Monday, October 11th, 23:00.
