Problem Statement

The task is to write a C program that computes the sum of n numbers input by the user.

Code Analysis

The solution should handle:

• Input validation to ensure only numeric values are accepted.
• Proper memory management if using dynamic allocation (though static allocation suffices for simplicity).
• Efficient handling of user input and output.

Proposed Solution

We will write a simple C program that:

1. Prompts the user for the number of elements (n).
2. Reads n integers from the user and calculates their sum.
3. Displays the result.

Code Development

Here is the complete C code for the solution:

#include 

// Function to compute the sum of n numbers
int sum_of_numbers(int n) {
    int sum = 0;  // Initialize sum to zero
    int number;

    // Loop to read n numbers
    for (int i = 0; i < n; i++) {
        printf("Enter number %d: ", i + 1);
        // Validate input
        if (scanf("%d", &number) != 1) {
            printf("Invalid input. Please enter an integer.\n");
            // Clear the input buffer
            while (getchar() != '\n');
            i--;  // Decrement i to repeat this iteration
            continue;  // Skip to the next iteration
        }
        sum += number;  // Add the number to sum
    }
    return sum;  // Return the final sum
}

int main() {
    int n;

    // Prompting user for the number of elements
    printf("Enter the number of elements: ");
    
    // Validate input for n
    while (scanf("%d", &n) != 1 || n <= 0) {
        printf("Please enter a valid positive integer for the number of elements: ");
        while (getchar() != '\n');  // Clear the input buffer
    }

    // Calculate the sum of n numbers
    int total_sum = sum_of_numbers(n);
    
    // Output the result
    printf("The sum of the entered numbers is: %d\n", total_sum);

    return 0;  // Exit the program
}

Code Explanation

• Includes: The #include <stdio.h> directive allows the use of standard input-output functions.
• sum_of_numbers Function: Contains the logic to read n integers and calculate their sum.
  • Utilizes a for loop to prompt the user for each integer.
  • Input validation ensures that only valid integers are accepted.
• Main Function:
  • Prompts the user for the total number of integers.
  • Validates the input for n to ensure it is a positive integer.
  • Calls sum_of_numbers to get the total sum and outputs the result.

Usage Example

To use the program, compile it with a C compiler and run it. You will be prompted to:

1. Enter the number of integers.
2. Input each integer consecutively.

Example interaction:

Enter the number of elements: 3
Enter number 1: 5
Enter number 2: 10
Enter number 3: 15
The sum of the entered numbers is: 30

Conclusion

This solution efficiently computes the sum of n integers with validation in place to handle erroneous input cases. The structure of the program adheres to best practices in C programming, promoting user-friendly interaction. For further enhancement, consider exploring advanced topics such as dynamic memory allocation or file input/output in C as guided by resources available on the Enterprise DNA Platform.