C++ Exercises: Find out the sum of an A.P. series

Last update on April 07 2025 13:01:23 (UTC/GMT +8 hours)

31. Sum of an A.P. Series

Write a C++ program to find the sum of an A.P. series.

Visual Presentation:

C++ Exercises: Find out the sum of an A.P. series

Sample Solution:-

C++ Code :

#include <iostream> // Include the input/output stream library

using namespace std; // Using standard namespace

int main() // Main function where the execution of the program starts
{
    int n1, df, n2, i, ln; // Declare integer variables n1, df, n2, i, ln
    int s1 = 0; // Declare and initialize an integer variable s1 to 0

    // Display message asking for input
    cout << "\n\n Find out the sum of A.P. series:\n";
    cout << "-----------------------------------------\n";
    cout << " Input  the starting number of the A.P. series: ";
    cin >> n1; // Read input for starting number of the A.P. series

    cout << " Input the number of items for  the A.P. series: ";
    cin >> n2; // Read input for the number of items for the A.P. series

    cout << " Input  the common difference of A.P. series: ";
    cin >> df; // Read input for the common difference of A.P. series

    // Calculate the sum of the A.P. series using the formula
    s1 = (n2 * (2 * n1 + (n2 - 1) * df)) / 2;

    ln = n1 + (n2 - 1) * df; // Calculate the last number in the series

    // Display the sum of the A.P. series
    cout << " The Sum of the  A.P. series are : " << endl;

    // Loop through the A.P. series and display each term
    for (i = n1; i <= ln; i = i + df) 
    {
        if (i != ln)
            cout << i << " + "; // Display series term followed by '+'
        else
            cout << i << " = " << s1 << endl; // Display last term followed by '=' and the calculated sum
    }
}

Sample Output:

 Find out the sum of A.P. series:                                      
-----------------------------------------                              
 Input  the starting number of the A.P. series: 1                      
 Input the number of items for  the A.P. series: 8                     
 Input  the common difference of A.P. series: 5                        
 The Sum of the  A.P. series are :                                     
1 + 6 + 11 + 16 + 21 + 26 + 31 + 36 = 148

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to compute the sum of an arithmetic progression given its first term, number of terms, and common difference.
Write a C++ program that reads the starting term, total terms, and difference, then outputs the A.P. series and its sum.
Write a C++ program to generate the terms of an A.P. series and calculate their total using a for loop.
Write a C++ program to calculate the sum of an arithmetic series using both a loop and the formula n/2*(first+last) for verification.

C++ Code Editor:

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