First year CS student trying to understand functions? - function

Question

I'm a first year CS student trying to understand functions, but I'm stuck on this problem where I have to use a function within another function. I have to create a program that checks all numbers from 0 to 100, and finds all the numbers that are evenly divisible by the divisor. I'm only allowed to have three functions, which are named, getDivisor, findNumbers and calcSquare. The output is supposed to be each number that is found (from 0 to 100) and the square of that number. I wrote a program (as seen below) that runs and answers the first question as to what is the divisor, but it stays open for only a few seconds and then closes when trying to compute which numbers are divisible by the divisor. I'm not sure exactly what I did wrong, but I would like to know so I can learn from my mistake! Please disregard the style, it's very sloppy, I usually go back and clean it up after I finish the program.
#include <iostream>
#include <string>
#include <cmath>
#include <iomanip>
using namespace std;
int getDivisor();
void findNumbers(int divisor, int lower, int upper, double &lowerSquared);
double calcSquare(int lower);
int main()
{
int divisor;
int lower = 0;
int upper = 100;
double lowerSquared;
divisor = getDivisor();
cout << "Here are the numbers, from 0 to 100, that are evenly divisble by "
<< divisor << ", and their squares:\n";
findNumbers(divisor, lower, upper, lowerSquared);
system("pause");
return 0;
}
int getDivisor()
{
int divisor;
cout << "Enter a divisor: ";
cin >> divisor;
return divisor;
}
void findNumbers(int divisor, int lower, int upper, double &lowerSquared)
{
while (lower < upper)
{
if (((lower / divisor) % 2) == 0)
{
lowerSquared = calcSquare(lower);
cout << setprecision(0) << fixed << setw(4) << lower << setw(8)<< lowerSquared << endl;
lower++;
}
else
{
lower++;
}
}
}
double calcSquare(int lower)
{
double lowerSquared;
lowerSquared = pow(lower, 2);
return lowerSquared;
}
The output should be (If the user enters 15). The output should be in a list format with the number on the left and the number squared to the right of it, but I don't know how to format properly on here... sorry:
Enter a divisor: 15
Here are the numbers, from 0 to 100, that are evenly divisble by 9, and their squares:
0 0
15 115
30 900
45 2025
60 3600
75 5625
90 8100
I appreciate any assistance!

Answer 1

Are you getting any error? because when running your code I get and exception.
Floating point exception(core dumped)
This exception happens because you are trying to do some illegal operation with float like divide by 0 in your if statement
to fix that simply assign lower number to 1 so the count starts from 1 not 0.
int lower = 1;
Also you might want to check the logic in the if statement because as it stands it wont give result you want.

Answer 2

/*Description:
This program is homework assignment to practice what I
learned from lecture #7a. It illustrates how to use
functions properly, specifically how to use functions
within other functions. The user is prompted to input
a divisor that once entered goes thru a function to
see if it is evenly divisble by every number from 0-100.*/
#include <iostream>
#include <string>
#include <cmath>
#include <iomanip>
using namespace std;
int getDivisor();
void findNumbers(int divisor, int lower, int upper, double &lowerSquared);
double calcSquare(int lower);
//====================== main ===========================
//
//=======================================================
int main()
{
int divisor;
int lower = 0;
int upper = 100;
double lowerSquared;
//Gets the divisor and assigns it to this variable.
divisor = getDivisor();
cout << "Here are the numbers, from 0 to 100, that are evenly divisble by "
<< divisor << ", and their squares:\n";
//Finds the numbers that are divisible by divisor,
//displays and shows their squares.
findNumbers(divisor, lower, upper, lowerSquared);
system("pause");
return 0;
}
/*===================== getDivisor ==========================
This function gets the divisor from the user so it can
assign it to the divisor variable to use in a later
function to check and see if it is divisible from 0-100.
Input:
Divisor
Output:
Divisor being assigned to divisor variable.*/
int getDivisor()
{
int divisor;
cout << "Enter a divisor: ";
cin >> divisor;
return divisor;
}
/*===================== findNumbers ==========================
This function runs a loop from 0 to 100 to check and see
if the divisor the user inputted is evenly divisble by
every number from 0 to 100. It also displays the numbers
that are evenly divisble and their squares with the help
of the calcSquare function.
Input:
There is no user input, other than the divisor from
the getDivisor function.
Output:
Numbers between 0 and 100 that are divisible by the
divisor and their squares.*/
void findNumbers(int divisor, int lower, int upper, double &lowerSquared)
{
while (lower <= upper)
{
if (lower % divisor == 0)
{
lowerSquared = calcSquare(lower);
cout << setprecision(0) << fixed << setw(4) << lower << setw(8) <<
lowerSquared << endl;
lower++;
}
else
{
lower++;
}
}
}
/*===================== calcSquare ==========================
This function squares the number from 0 to 100 (whatever
number that might be in the loop) that is divisible by the
user entered divisor, so that it may assign it to the
lowersquared variable in the findNumbers function to be
used in the output.
Input:
Number from 0 to 100 that is divisible by user entered
divisor
Output:
Number from 0 to 100 squared.*/
double calcSquare(int lower)
{
double lowerSquared;
lowerSquared = pow(lower, 2);
return lowerSquared;
}
//==========================================================
/*OUTPUT:
Enter a divisor: 15
Here are the numbers, from 0 to 100, that are evenly divisble by 15, and their
squares:
0 0
15 225
30 900
45 2025
60 3600
75 5625
90 8100
Press any key to continue . . .
*/
//==========================================================