ECE 175: Computer Programming for Engineering Applications

ECE 175: Computer Programming for Engineering Applications

Spring 2016

Lab Assignment #6 (Thursday session)

complete solutions correct answers key 

Problem 1 (15 points): Develop a C program to find a lower triangular matrix of a given matrix A and a product of all diagonal elements of A. 

Lower triangular matrix is a 2D array such that every elements above the main diagonal = 0.

Your program must be written using loops such that it works with any given SIZE of a matrix and should use the following prototypes:

#define SIZE 3          //Change this to match the size of matrix used in main()

//this function is to create lower triangular matrix of A (create A_lower)

void findLower(double A[][SIZE], double A_lower[][SIZE]);

//this function is to find product of all diagonal elements

void ProductDiagonal(double x[][SIZE], double *product);

//this function is to print 2D array x in a matrix format

void PrintMatrix(double x[][SIZE]);

Sample code execution 2:

M =

  9.10   13.40    5.20    2.70

  1.80   11.00    7.50    6.90

  3.50    7.30    4.60    1.25

  6.50    0.00    7.80   10.00

lower(M) =

  9.10    0.00    0.00    0.00

  1.80   11.00    0.00   0.00

  3.50    7.30    4.60    0.00

  6.50    0.00    7.80   10.00

Product of all diagonal elements = 4604.600

Press any key to continue . . .

You will initialize the 2D array (matrix) directly in your (main) code for given matrices (2D arrays) shown in sample code executions. 

Sample code execution 1:

M =

  0.71   -0.71    0.85

  0.61    0.61   -0.50

  0.35    0.35    0.87

lower(M) =

  0.71    0.00    0.00

  0.61    0.61    0.00

  0.35    0.35    0.87

Product of all diagonal elements = 0.377

Press any key to continue . . .

Sample code execution 3:

Problem 2 (15 points):

A palindrome is a word that reads the same forward as it does backward.

-          An example of a valid palindrome is the word "racecar".

-          An example of a word that is not a palindrome is "trust" (it reads backwards as "tsurt").

Develop a C program that

-          Ask a user to enter one word

-          Decide whether the entered word is a palindrome

-          Be interactive (q to quit, others to continue)

Note: assume that a maximum number of characters for one word is 50

See sample code execution below:

red – entered by a user

Enter a word: racecar

racecar is a palindrome

Press q/Q to quit, others to continue: y

Enter a word: trust

trust is NOT a palindrome

Press q/Q to quit, others to continue: t

Enter a word: detartrated

detartrated is a palindrome

Press q/Q to quit, others to continue: s

Enter a word: minimum

minimum is NOT a palindrome

Press q/Q to quit, others to continue: r

Enter a word: rotator

rotator is a palindrome

Press q/Q to quit, others to continue: a

Enter a word: 175ece571

175ece571 is a palindrome

Press q/Q to quit, others to continue: c

Enter a word: testset

testset is a palindrome

Press q/Q to quit, others to continue: q