﻿ C++ Exercises: Check whether a given number is Abundant or not - w3resource

C++ Exercises: Check whether a given number is Abundant or not

C++ Numbers: Exercise-2 with Solution

Write a program in C++ to check whether a given number is Abundant or not.

Pictorial Presentation:

Sample Solution:

C++ Code :

``````#include <bits/stdc++.h>
using namespace std;
int getSum(int n)
{
int sum = 0;
for (int i=1; i<=sqrt(n); i++)
{
if (n%i==0)
{
if (n/i == i)
sum = sum + i;
else // Otherwise take both
{
sum = sum + i;
sum = sum + (n / i);
}
}
}
sum = sum - n;
return sum;
}
bool checkAbundant(int n)
{
return (getSum(n) > n);
}
int main()
{
int n;
cout << "\n\n Check whether a given number is an Abundant number:\n";
cout << " --------------------------------------------------------\n";
cout << " Input an integer number: ";
cin >> n;
checkAbundant(n)? cout << " The number is Abundant.\n" : cout << " The number is not Abundant.\n";
return 0;
}
``````

Sample Output:

```Check whether a given number is an Abundant number:
--------------------------------------------------------
Input an integer number: 35
The number is not Abundant.
```

Flowchart:

C++ Code Editor:

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C++ Programming: Tips of the Day

How to use the PI constant in C++?

On some (especially older) platforms (see the comments below) you might need to

#define _USE_MATH_DEFINES and then include the necessary header file:
`#include<math.h>`

and the value of pi can be accessed via:

`M_PI`

In math.h (2014) it is defined as:

`# define M_PI           3.14159265358979323846  /* pi */`

but check your math.h for more. An extract from the "old" math.h (in 2009):

```/* Define _USE_MATH_DEFINES before including math.h to expose these macro
* definitions for common math constants.  These are placed under an #ifdef
* since these commonly-defined names are not part of the C/C++ standards.
*/```

However:

1. on newer platforms (at least on my 64 bit Ubuntu 14.04) I do not need to define the _USE_MATH_DEFINES
2. On (recent) Linux platforms there are long double values too provided as a GNU Extension:
`# define M_PIl          3.14159265358979323846`

Ref: https://bit.ly/3G4BgzQ