Example: Sum of Squares using Iteration in C

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// Sum of Squares using Iteration
#include <stdio.h>

int main() {
    int n;
    long long sum_of_squares = 0; // Use long long for sum to prevent overflow for larger n
    int i;

    // Step 1: Prompt user for input
    printf("Enter a positive integer (n): ");
    
    // Step 2: Read the value of n
    if (scanf("%d", &n) != 1 || n < 1) {
        printf("Invalid input. Please enter a positive integer.\n");
        return 1; // Indicate an error
    }

    // Step 3: Iterate from 1 to n, square each number, and add to sum
    for (i = 1; i <= n; i++) {
        sum_of_squares += (long long)i * i; // Cast to long long before multiplication to prevent overflow
    }

    // Step 4: Print the result
    printf("The sum of squares up to %d is: %lld\n", n, sum_of_squares);

    return 0;
}