Question

Use C++ to implement the following program about Prime Factorization of a Number. Do BOTH parts of the problem or you will lose points. Provide comments to explain each step.

a. Write a function that takes as a parameter a positive integer and returns a list (array) of the prime factors of the given integer. For example, if the parameter is 20, you should return 2 2 5.

b. Write a function that tests the above function by asking the user for input and displaying the output to screen. Your function should display the following menu:

1) Find the prime factorization of a number.

2) Quit.

Answer 1

PROGRAM:

# include <iostream>

# include <math.h>

//method for finding the prime factor

void primeFactorsOfANumber(int num)

{

//no prime factor exists for 0 and 1

if(num==0||num==1)

{

std::cout<<"\n No primefactor\n";

}

else{

//if the number is even,print 2 and divide the number by 2

while (num%2 == 0)

{

std::cout<< 2 <<" ";

num = num/2;

}

  

   //initialize i=3 and i less than squareroot of the number

for (int i = 3; i <= sqrt(num); i = i+2)

{

//remainder of the number divided by i equal to 0

while (num%i == 0)

{

std::cout<< i<<" ";

num = num/i;

}

}

  

//number is greater than 2,print the number

if (num > 2)

{

std::cout<< num<<" ";

}

}

}

// Driver program

int main()

{

int num;

int choice;

do{

//menu

std::cout<<"\n1.Find The primeFactorial of a number\n";

std::cout<<"2. Quit\n";

std::cout<<"Enter your choice: ";

std::cin>>choice;

switch(choice)

{

case 1:

std::cout<<"\nEnter the NUmber : \n";

std::cin>>num;

//calling the function primeFactorsOfANumber

primeFactorsOfANumber(num);

break;

case 2:

//exit

return 0;

break;

}

}

while(1);

return 0;

}

OUTPUT:

1.Find The primeFactorial of a number

2. Quit

Enter your choice: 1

Enter the NUmber :

11

11

1.Find The primeFactorial of a number

2. Quit

Enter your choice: 1

Enter the NUmber :

24

2 2 2 3

1.Find The primeFactorial of a number

2. Quit

Enter your choice: 2

Program ended with exit code: 0