avg.c

/* omg -- a C program to average things -- by Rick Branson -- public domain 'n shit */

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

#define BUFSZ		1024 * 32 
#define ARRAY_ALLOC_SZ	1024 * 32

int main(int argc, char **argv)
{
	int alloced = 0;
	int i = 0;
	int x;
	float *nums = NULL;
	float tmp = 0;
	char s[BUFSZ];
	char *s2;
	double sum = 0;

	while (fgets(s, BUFSZ, stdin))
	{
		if (i == alloced)
		{
			alloced += ARRAY_ALLOC_SZ;
			nums = realloc(nums, alloced * sizeof(float));
		}

		s2 = s;

		/* handle leading spaces */
		if (s[0] == ' ')
		{
			while (*s2++)
			{
				if (*s2 != ' ')
					break;
			}
		}

		sscanf(s2, "%f", &tmp);
	
		if (tmp)
		{
			nums[i++] = tmp;
			tmp = 0;
		}
	}

	for (x = 0; x < i; x++)
	{
		sum += nums[x];
	}

	printf("%.10f\n", sum / i);
}