Thread: homework assignment; need help, what am i missing(!)?

the lesson is about using arrays

1) Write a program that will take N positive numbers
from the user and print the average of the numbers.
The input can be terminated by entering a negative
number. You can assume N<1000

the code i have, thus far (not working):

Code:

#include <stdio.h>
#include <string.h>
int main(int argv, char** argc){
    int n, i;
    float sum = 0.0, average;
    char num[1000];
    for (i = 0; i < 1000; ++i)
    {
        printf("%d. Enter number: ", i + 1);
        scanf("%f", &n, &num[i]);
        if (n < 0)
            {
                break;
            }
        
    }
    sum += num[i];
    average = sum / strlen(num);
    printf("Average = %.2f", average);
    return 0;
}

of course it's due today so "URGENT!"

You should explain how it does not work.

Let's start by looking at the warnings generated by the compiler. This is what I got:

Code:

/*
main.c||In function 'main':|
main.c|10|warning: format '%f' expects type 'float *', but argument 2 has type 'int *'|
main.c|10|warning: too many arguments for format|
main.c|3|warning: unused parameter 'argv'|
main.c|3|warning: unused parameter 'argc'|
||=== Build finished: 0 errors, 4 warnings ===|
*/

The warnings for line 10 are the most relevent. You're passing an *int and a *char to "scanf()", but it is expecting to read just one value (which is a float (%f), at that).

If you want to read values directly into your array, you don't need to use 'n' at all.

Your array should be either int or float (depending on the requirements of the assignment).

I don't understand why you're using character arrays and string functions for a mathematical program.

I'd recommend starting over, and building up your program gradually, testing as you go.

First, start with just two loops - one that only reads values into the array, and one that only prints the values of the array.

When you have this working, add a bit more code to find the sum of all values in the array. Print out the sum and verify it is correct.

When you have this working, add a bit more code to find the average. Print out the average and verify it is correct.

Then you're done.

A development process

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of course it's due today so "URGENT!"

Shouting "urgent!" will not do you any favors. It's your responsibility to make sure you have enough time to complete your assignments.