program to read N integers (zero, +ve and -ve) into an Array

/* Write a C program to read N integers (zero, +ve and -ve) *
* into an array A and to *
* a) Find the sum of negative numbers *
* b) Find the sum of positive numbers and *
* c) Find the average of all input numbers *
* Output the various results computed with proper headings */

#include stdio.h
#include conio.h
#define MAXSIZE 10

void main()
{
int array[MAXSIZE];
int i, N, negsum=0, posum=0;
float total=0.0, averg;

clrscr();

printf ("Enter the value of N\n");
scanf("%d", &N);

printf("Enter %d numbers (-ve, +ve and zero)\n", N);
for(i=0; i< N ; i++)
{
scanf("%d",&array[i]);
fflush(stdin);
}

printf("Input array elements\n");
for(i=0; i< N ; i++)
{
printf("%+3d\n",array[i]);
}

/* Summing begins */
for(i=0; i< N ; i++)
{

if(array[i] < 0)
{
negsum = negsum + array[i];
}
else if(array[i] > 0)
{
posum = posum + array[i];
}
else if( array[i] == 0)
{
;
}
total = total + array[i] ;
}

averg = total / N;
printf("\nSum of all negative numbers = %d\n",negsum);
printf("Sum of all positive numbers = %d\n", posum);
printf("\nAverage of all input numbers = %.2f\n", averg);

} /*End of main()*/
/*-------------------------------------
Output
Enter the value of N
5
Enter 5 numbers (-ve, +ve and zero)
5
-3
0
-7
6
Input array elements
+5
-3
+0
-7
+6

Sum of all negative numbers = -10
Sum of all positive numbers = 11

Average of all input numbers = 0.20
--------------------------------------*/

This program is a intro for Array elements. It is a good example for array inputs and execution. The beauty of C language lies in Arrays and pointers. So i stress the readers to concentrate more on programs from here as all are in the order of increasing complexity

The first thing to note is the usage of Symbolic constant MAXSIZE to specify the size of array. If you want to know more about array size and different ways of its specification, Use the search box.

In this program we are initializing all the values to a preset value. By doing so we are manually flusing all the variables. There is a chance that these variables might be assigned some value at some time of execution of other programs. Those will be cleared.

Now we are using a for loop to input the array elements. Here the point to note is the usage of fflush() function, which clears all the input buffers after taking the input. It is advisory that we keep clearing both input and output buffers periodically to aviod any variable over lap.

Then we are reading each element of array and adding using a for loop. We use an else.. if to seperate positive and negative numbers and then add.