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C++ Exercises: Calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n)

C++ For Loop: Exercise-13 with Solution

Write a program in C++ to calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n).

Pictorial Presentation:

C++ Exercises: Calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n)

Sample Solution :-

C++ Code :

#include <iostream>
using namespace std;

int main()
{
    int i, j, n, sum = 0, tsum;
    cout << "\n\n Find the sum of the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n):\n";
    cout << "------------------------------------------------------------------------------------------\n";
    cout << " Input the value for nth term: ";
    cin >> n;
    for (i = 1; i <= n; i++) 
	{
        tsum = 0;
        for (j = 1; j <= i; j++) 
		{
            sum += j;
            tsum += j;
            cout << j;
            if (j < i) 
			{
                cout << "+";
            }
        }
        cout << " = " << tsum << endl;
    }
    cout << " The sum of the above series is: " << sum << endl;
}

Sample Output:

 Find the sum of the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (
1+2+3+4+...+n):                                                        
-----------------------------------------------------------------------
-------------------                                                    
 Input the value for nth term: 5                                       
1 = 1                                                                  
1+2 = 3                                                                
1+2+3 = 6                                                              
1+2+3+4 = 10                                                           
1+2+3+4+5 = 15                                                         
 The sum of the above series is: 35 

Flowchart:

Flowchart: Calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n)

C++ Code Editor:

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Previous: Write a program in C++ to calculate the sum of the series (1*1) + (2*2) + (3*3) + (4*4) + (5*5) + ... + (n*n).
Next: Write a program in C++ to find the sum of series 1 - X^2/2! + X^4/4!-.... upto nth term.

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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