Question

Below is the code for two programs in C language, I was trying to make proper comments within the code so that someone can understand it. Please review the comments within the code and let me know if it makes good sense. Let me know if I need to make any changes to the comments! Thank you.

PROGRAM 1:

/* program calculates harmonic mean for 10 numbers entered by the user */

/* if illegal value (x<0) is entered, the user is asked to re-enter a valid number */

#include "stdafx.h"

#include <math.h>

#include <stdio.h>

      int main()

      {

            int n = 10;

            float x, prod = 1, gm;          /* declaring variables, x is for taking input */

            for (int i = 1; i <= n; i++)      /* i = counter starting at 1, loop runs              10 times by increment of 1 */

            {

                  printf("enter a number\n");    /* asking user to enter number */

                  scanf_s("%f", &x); /* number entered by user */

                  if (x < 0) /* (x<0) for invalid entry */

                  {

                  printf("you entered an invalid number\n");

      i--;  /*i = i – 1, the count will be reduced to accommodate a new   entry by the user*/

                  continue;

                  /* using continue to ask the user to re-enter a valid  number */

      /* continue statement forces next iteration of the loop and skips   any remaining statements in the loop */

                  }

                  prod *= x; /* prod = prod * x */

            }

gm = pow(prod, 10 / n); /* formula for geometric mean using previous statements */

            printf("the harmonic mean is %f:\n",gm); /* displaying result of geometric mean */

            return 0;

      }

PROGRAM 2:

/* program to find the average speed and the maximum height */

/* information is obtained from the data file */

#include "stdafx.h"

#include <math.h>

#include <stdio.h>

int main()

{

      int speed, N;

      FILE*t1;     /* FILE declaration defines file pointer */

      float height, max, sum = 0, avg_speed;

      t1 = fopen("input.txt", "r");/* fopen function used to obtain the information     needed to assign file pointer to the file  */

      fscanf(t1, "%d", &N); /* fscanf function is used to scan the file */

      for (int k = 1; k <= N; k++)

      {

            fscanf(t1, "%d %f", &speed, &height); /* fscanf function is used to scan               the file */

            if (k == 1)

                  max = height;

            if (height > max)

                  max = height;

            sum += speed;

      }

      avg_speed = sum / N;

      printf("the average is %f and max is %f", avg_speed, max); /* displaying result of      average speed and maximum value of height */

      return 0;

}

Answer 1

The comments are perfect. As most of comments are a single line comment, you can use the symbol // instead of /* ... */ before a comment.

Also, please comment why you used the header files. For example,

#include<math.h> // used for pow() function
#include<stdio.h> // used for input and output

These are just minor changes. Otherwise, everything is correct.