Page 482 - Computer science 868 Class 12
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4. A base class Array2D is defined to store numbers in a 3 × 3 matrix. A derived class Upper is defined to generate the upper triangle
matrix from matrix a[][]. A square matrix whose all elements below the principle diagonal is 0 is called upper triangle matrix.
Eg. if matrix a[][] is
1 2 3
4 5 6
7 8 9
then its Upper triangle matrix will be
1 2 3
0 5 6
0 0 9
Some of the members of the class are given below.
Class name : Array2D
Data Members/Instance variables
a[][] : integer two dimensional matrix
Methods/Member Functions
Array2D(int c[][]) : Initialises matrix a[][]
void print() : Prints matrix a[][]
Class name : Upper
Data Members/Instance variables
b[][] : integer matrix to store the upper triangle matrix of a[][]
Methods/Member Functions
Upper(.....) : Initialises data members of base and derived classes
void generate() : Generates the upper triangle matrix and stores it in b[][]
void print() : Prints both the original and upper triangle matrices
Using the concept of inheritance, specify the class Upper giving details of the constructor and the member functions void
generate() and void print(). Base class and main method need not to be written.
5. A base class Word is defined to store word and print it. Design a derived class ChangeCase to generate a new word by changing
the case of the original word. The details of both classes are given below.
Class name : Word
Data Members
str : stores the word
len : stores the length of the word
Member Functions
Word(String s) : constructor to initialise word
void display() : displays the original word
Class name : ChangeCase
Data Members
nstr : stores the changed word
Member Functions
ChangeCase (String s) : constructor to initialise both base and derived class data members
void change() : changes case of each character in word str and stores it in nstr
void display() : displays both the words
Using the concept of inheritance, specify the class ChangeCase giving details of the constructor and the member functions void
change() and void display(). Base class and main method need not to be written.
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6. A base class Quadratic is defined to enter the numerical coefficients a, b, c of a quadratic equation ax + bx + c and calculate the
2
discriminant d as b - 4ac. The details of the class is given below.
Class name : Quadratic
Data Members
double a, b, c, d : To store the coefficients and discriminant
Quadratic(double aa, double bb, double cc) : Constructor to initialize the coefficients
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void calculate : Calculates discriminant of the quadratic equation ‘d’ as b - 4ac
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