C Programming While Loop Assignment - c

Question

Question: Take n as input. Then take n numbers as input and print the summation of those n numbers. But this time output as the format below.
Example:
Input:
4
1 5 3 -4
output 1 + 5 + 3 – 4 = 5
I got the output value correctly, but I do not know how am I going to show the actual summation sequence, especially in one line....
My Code:
main ()
{
int n,m,cnt=0,sum=0;
printf("Input: ");
scanf("%d", &n);
while(cnt<n)
{
scanf("%d\b", &m);
sum=sum+m;
cnt=cnt+1;
if(m>0 && m!=n)
{
printf("\b+",m);
}
else if (m<0)
{
printf("%d",m);
}
}
printf("=%d\n\n",sum);
}

Answer 1

Here's a sample solution that I came up with:
#include <stdio.h>
int main() {
int n = 0,
count = 0,
sum = 0;
int first = 1;
printf("How many numbers do you wish to sum? " );
scanf("%d", &n);
while (count < n) {
int m;
scanf("%d\b", &m);
if (!first) {
if (m < 0) {
printf("- %d ", -m);
} else {
printf("+ %d ", m);
}
} else {
first = !first;
printf("%d ", m);
}
sum += m;
count++;
}
printf("= %d\n\n", sum);
return 0;
}
Here's a sample execution:
$ gcc stackoverflow.c -o stackoverflow
$ ./stackoverflow
How many numbers do you wish to sum? 5
1 -2 -3 4 10 -40
1 - 2 - 3 + 4 + 10 = 10

Answer 2

If the summation sequence is to be printed after the input, the problem could be solved by using a dynamically allocated array int[] of length n in which the input is read. After the input is read, the actual summation can be done and the summands can be printed, as they have been stored in the array. The dynamic allocation can be done with the malloc function; you would also have to use the free function after the summation.

Answer 3

Catch!:)
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
unsigned int n = 0;
printf( "Enter number of items (0-exit): " );
scanf( "%u", &n );
if ( n != 0 )
{
int items[n];
printf( "Enter %u numbers: ", n );
unsigned int i = 0;
while ( i < n && scanf( "%d", &items[i] ) == 1 ) ++i;
int sum = 0;
_Bool first = 1;
n = i;
for ( i = 0; i < n; i++ )
{
sum += items[i];
if ( !first || items[i] < 0 )
{
printf( "%c ", items[i] < 0 ? '-' : '+' );
}
if ( first ) first = 0;
printf( "%u ", ( unsigned int )abs( items[i] ) );
}
printf( "= %d\n", sum );
}
return 0;
}
The output might look like
Enter number of items (0-exit): 4
Enter 4 numbers: 1 5 3 -4
1 + 5 + 3 - 4 = 5

Answer 4

#include <stdio.h>
int main()
{
int num;
int answer=0;
do
{
printf("\nEnter the number(s) to be added: (enter 0 to quit) ");
scanf("%d", &num);
answer=answer + num;
}
while (num!=0);
printf("Answer is %d", answer);
return 0;
}
Advantage of above approach is that you don't require an array and don't have to declare the no. of values that you are adding. Sort of like adding using a calculator where you simply press the "=" button when you are done.