C programming Arrays with Functions

Question

My program is suppose to read the Numbers text file which is where I have listed my numbers and store them into an array then display in 5 columns. My problem is that it wont display the array at all. Im not sure why.

#include <stdio.h>
#include <stdlib.h>
#define ELEMENTS 100

void fillArray(FILE *, double [], double *);
void printArray(double [], double); 
double findMIN(double [], double);
double findMAX(double [], double);

int main()
{
    FILE *doublefp;
    double values[ELEMENTS];
    double elements;
    int status;

    status = fopen_s(&doublefp, "Numbers.txt", "r");
    if (status != 0)
    {
        printf("Unable to open the file Numbers.txt\n");
        system("PAUSE");
        exit(99);
    }

    fillArray(doublefp, values, &elements);
    printArray(values, elements);


    printf("The minimum value is %d\n", findMIN(values, elements));

    printf("The maximum value is %d\n", findMAX(values, elements));

    system ("PAUSE");
    return 0;

}

double findMIN(double nums[], double element)
{
    int i;
    double min = nums[0];

    for (i = 1; i < element; i++)
    if (min > nums[i])
      min = nums[i];

  return (min);
}

double findMAX(double nums[], double element)
{
    int i;
    double max = nums[0];

    for (i = 1; i < element; i++)
    if (max < nums[i])
      max = nums[i];

  return (max);

}

void fillArray (FILE *fp, double nums[], int *count)
{
    double number;

    printf("Enter up to %d integers press the F6 key to end input. \n", ELEMENTS);
    *count = 0;
    while (fscanf_s(fp, "%d", &nums[*count]) != EOF)
    {
        (*count)++;
    }

}

void printArray (double nums[], double elements)
{
    int count;

    printf("Values in array:\n");
    for (count = 0; count < elements; count++)
    {
        printf("%5d ",nums[count]);
        if ((count+1)% 10 == 0)
           printf("\n");
    }
    printf("\n");printf("\n");


}

My numbers are in a text file listed like this: 23.53 56.8 12.1 677.23 122.09 788.18 123.25 65.12 98.18 622.27 366.34 433.45 844.56 244.67 544.78 290.10 189.28 522.17 321.33 178.76

Answer 1

Basically, double elements; needs to be int elements

Here &elements is a double * , the function fillArray expects an int *

fillArray(doublefp, values, &elements);

Did you turn the warnings on in your compiler?

Also, in printArray , elements is defined as a double when it should be an int .

Same with findMax and findMin .

And printf("%5d ",nums[count]); should be printf("%lf ",nums[count]);

Turn on all the warnings in your complier, fix them and then ask again if it doesn't work.

Answer 2

Two problems:

1) Your "printf()" format statement should use "%d" to print integers, and "%lf" to print doubles. You're not doing this consistently.

2) You're better off using an "int" for "counting numbers", instead of double. Unfortunately, you're not doing this consistently, either.

SUGGESTED CHANGES:

#include <stdio.h>
#include <stdlib.h>
#define ELEMENTS 100

void fillArray(FILE * fp, double values [], int * count);
void printArray(double values[] int count); 
double findMIN(double values[], int count);
double findMAX(double values[], int count);

int main()
{
    FILE *doublefp;
    double values[ELEMENTS];
    int elements;
    int status;

    status = fopen_s(&doublefp, "Numbers.txt", "r");
    if (status != 0)
    {
        printf("Unable to open the file Numbers.txt\n");
        system("PAUSE");
        exit(99);
    }

    fillArray(doublefp, values, &elements);
    printArray(values, elements);


    printf("The minimum value is %f\n", findMIN(values, elements));
    printf("The maximum value is %f\n", findMAX(values, elements));

    system ("PAUSE");
   ...   

double findMIN(double nums[], int count)
   ...

void fillArray (FILE *fp, double nums[], int *count)
{
    printf("Enter up to %d integers press the F6 key to end input. \n", ELEMENTS);
    *count = 0;
    while (fscanf_s(fp, "%f", &nums[*count]) != EOF)
    {
        (*count)++;
    }
    ...