How to Write a C Program to Calculate the Sum of Squares from 1 to N

If you're new to C programming or need to write a program that calculates the sum of squares from 1 to N, this article is for you. We'll walk through the steps and provide a complete C program that accomplishes this task. By the end, you'll have a solid understanding of how to use user input, loops, and basic arithmetic operations in C.

Understanding the Problem

The goal is to create a C program that takes a number N as input and outputs the sum of the squares of all numbers from 1 to N. For example, if the input is 4, the output should be 30, because 12 22 32 42 1 4 9 16 30.

How to Write the Program

Let's break down the steps needed to write this program:

Step 1: Include the Necessary Libraries

First, include the standard input-output library which is required for using printf and scanf functions.

#include stdio.h

Step 2: Prompt the User for Input

Use the printf function to prompt the user to enter a number.

printf("Enter a number: ");

Step 3: Read the User's Input

Use the scanf function to read the integer input from the user and store it in a variable.

scanf("%d", N);

Step 4: Initialize the Sum Variable

Create an integer variable to store the sum of the squares and initialize it to 0.

int sum 0;

Step 5: Use a Loop to Calculate the Sum of Squares

Use a loop to iterate from 1 to N. Inside the loop, calculate the square of each number and add it to the sum.

for (int i 1; i sum i * i;
}

Step 6: Output the Result

Use the printf function to display the final sum.

printf("The sum of squares from 1 to %d is: %d", N, sum);
}

Complete C Program

#include stdio.hint main() {    int N, sum  0;    // Prompt the user for input    printf("Enter a number: ");    // Read the integer input from the user    scanf("%d", N);    // Calculate the sum of squares from 1 to N    for (int i  1; i 

Explanation

In this program, we have included the stdio.h library, which is necessary for using printf and scanf. The main function is where the program begins execution.

We declare an integer variable N to store the user's input and initialize an integer variable sum to 0. This variable will be used to accumulate the sum of the squares.

The printf function is used to prompt the user to enter a number, and the scanf function reads the integer input from the user and stores it in the variable N.

The for loop iterates from 1 to N, where inside the loop, we calculate the square of each number (i * i) and add it to the sum variable.

The final printf function outputs the result, displaying the sum of squares from 1 to N.

Example Output

If the user inputs 4, the output will be:

The sum of squares from 1 to 4 is: 30

This program effectively computes the sum of squares as required, providing a clear and concise solution to the problem.

Conclusion

Writing a C program to calculate the sum of squares from 1 to N is a great exercise for beginners to practice using user input, loops, and basic arithmetic operations. By following the steps outlined in this article, you can create your own program to solve this problem and gain valuable programming experience.