C programs to find the sum and average of the numbers until 0 is entered, are given here. Suppose the input numbers are 5, 10, 9, 0, then the sum = (5 + 10 + 9) = 24 and average = (5 + 10 + 9) / 3 = 8.

## 1. Algorithm to find the sum and average of the numbers until 0 is entered

1. Set sum = 0, count = 0.

2. Take a number n as input.

3. Perform sum = sum + n.

4. Check if n = 0

5. If step 4 is true declare sum and as the sum and (sum / count) as the average of the numbers entered.

6. If step 4 is false, perform count = count + 1 and go to step 2

## 2. Pseudocode to find the sum and average of the numbers until 0 is entered

1. Procedure sumAverage():

2. sum := 0

3. count := 0

4. n := Input()

5. Repeat until n = 0

6. sum := sum + n

7. count := count + 1

8. n := Input()

9. avg := (sum / count)

10. Return sum, avg

11. End Procedure

## 3. Time complexity to find the sum and average of the numbers until 0 is entered

Time Complexity: O(n)

Here n is the number of terms.

## 4.1. C Program to find the sum and average of the numbers until 0 is entered using iteration

Code has been copied
/********************************
alphabetacoder.com
C program to find average and sum
of numbers until 0 is entered
*********************************/

#include <stdio.h>

int main() {
// declare variables
int n, count, sum;

// initialize
sum = 0;
count = -1;

// keep taking input
// until 0 is entered
do {
// take input
printf("Enter a number: ");
scanf("%d", & n);

// add to sum
sum = sum + n;

// increment the value of number count
count++;

} while (n != 0);

// display the sum and average
printf("\nTotal number entered: %d\n", count);
printf("Sum: %d\n", sum);
printf("Average: %lf\n", (double) sum / count);

return 0;
}


Output

Enter a number: 8

Enter a number: 3

Enter a number: 5

Enter a number: -4

Enter a number: 3

Enter a number: 1

Enter a number: 0

Total number entered: 6

Sum: 16

Average: 2.666667

## 4.2. C Program to find the sum and average of the numbers until 0 is entered using recursion

Code has been copied
/*******************************************
alphabetacoder.com
C program to find sum and average of
numbers until 0 is entered using recursion
********************************************/

#include <stdio.h>

void findSumAverage(int sum, int count) {
// take input
int n;
printf("Enter a number: ");
scanf("%d", & n);

// keep taking input
// until 0 is entered
if (n == 0) {
printf("\nTotal numbers entered: %d\n", count);
printf("Sum: %d\n", sum);
printf("Average: %lf\n", (double) sum / count);
} else {
// add input to sum and increment count
sum += n;
count++;
findSumAverage(sum, count); // recursive call
}
}

int main() {
// declare and initialize variables
int sum = 0, count = 0;

// call function to display result
findSumAverage(sum, count);

return 0;
}


Output

Enter a number: 1

Enter a number: 3

Enter a number: 5

Enter a number: 0

Total number entered: 3

Sum: 9

Average: 3.000000