sum and mean of the number in loop

[AkiraC]

Hi there, so I made this program that ask users to enter a series of number and then the program will show the total number that the user entered, the sum and mean of the number. Below is my coding:

#include<stdio.h>
#include<stdlib.h>
#pragma warning (disable:4996)
#define SENTINEL -999

void main()
{
	int n=0, i=0, sum = 0;
	float mean = 0;

	do {
		printf("Give me any integer (-999 to stop): ");
		scanf("%d", &n);
		if (n != SENTINEL)
			i += 1;
		    sum = sum + n;
		    mean = sum / i;
	} while (n != SENTINEL);


	printf("total number you has keyed in : %d\n", i);
	printf("sum of the numbers: %d\n", sum);
	printf("Mean of the numbers: %.3f\n", mean);

	system("pause");
}

For the input, I put 2 and 4, so total number that I had keyed in is 2 and the sum is 6,while the mean is 3.000. However, the program gave me the wrong sum and mean.
I think there's problem with the sum and mean coding, any help will be appreciated and thank you for helping.

[lastchance]

If you encounter the sentinel then you need to exit the loop immediately, not continue to the end of the loop.

Change
if (n != SENTINEL)
to
if (n == SENTINEL) break;

That will make it "work" (well, do what you intend anyway), but there's a lot still wrong with the code.

Also, you only need to compute the mean ONCE, not on every loop.

[seeplus]

You need L15-16 within the body of the if statement. As it stands if n is the sentinel then sum also includes the sentinel. mean should be calculated once the loop has terminated.

Consider:

#include <stdio.h>
#include <stdlib.h>

#pragma warning (disable:4996)
#define SENTINEL -999

void main()
{
	int n = 0, i = 0;
	float sum = 0;

	do {
		printf("Give me any integer (-999 to stop): ");
		scanf("%d", &n);
		if (n != SENTINEL) {
			++i;
			sum += n;
		}
	} while (n != SENTINEL);

	printf("total number you has keyed in : %d\n", i);
	printf("sum of the numbers: %.0f\n", sum);
	printf("Mean of the numbers: %.3f\n", sum / i);

	//system("pause");
}