﻿ C++ : Display the n terms of harmonic series and their sum # C++ Exercises: Display the n terms of harmonic series and their sum

## C++ For Loop: Exercise-22 with Solution

Write a program in C++ to display the n terms of harmonic series and their sum.
1 + 1/2 + 1/3 + 1/4 + 1/5 ... 1/n terms

Pictorial Presentation: Sample Solution:-

C++ Code :

``````#include <iostream>
using namespace std;

int main()
{
int i, n;
float s = 0.0;
cout << "\n\n Display n terms of harmonic series and their sum:\n";
cout << " The harmonic series: 1 + 1/2 + 1/3 + 1/4 + 1/5 ... 1/n terms\n";
cout << "-----------------------------------------------------------------\n";
cout << " Input number of terms: ";
cin >> n;
for (i = 1; i <= n; i++)
{
if (i < n)
{
cout << "1/" << i << " + ";
s += 1 / (float)i;
}
if (i == n)
{
cout << "1/" << i;
s += 1 / (float)i;
}
}
cout << "\n The sum of the series upto " << n << " terms: " << s <<

endl;
}
``````

Sample Output:

``` Display n terms of harmonic series and their sum:
The harmonic series: 1 + 1/2 + 1/3 + 1/4 + 1/5 ... 1/n terms
-----------------------------------------------------------------
Input number of terms: 5
1/1 + 1/2 + 1/3 + 1/4 + 1/5
The sum of the series upto 5 terms: 2.28333
```

Flowchart: C++ Code Editor:

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## C++ Programming: Tips of the Day

What is a smart pointer and when should I use one?

This answer is rather old, and so describes what was 'good' at the time, which was smart pointers provided by the Boost library. Since C++11, the standard library has provided sufficient smart pointers types, and so you should favour the use of std::unique_ptr, std::shared_ptr and std::weak_ptr.

There was also std::auto_ptr. It was very much like a scoped pointer, except that it also had the "special" dangerous ability to be copied - which also unexpectedly transfers ownership.

It was deprecated in C++11 and removed in C++17, so you shouldn't use it.

```std::auto_ptr<MyObject> p1 (new MyObject());
std::auto_ptr<MyObject> p2 = p1; // Copy and transfer ownership.
// p1 gets set to empty!
p2->DoSomething(); // Works.
p1->DoSomething(); // Oh oh. Hopefully raises some NULL pointer exception.
```

Ref : https://bit.ly/3mc9GHE