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

int avg(size_t N, int *a)
{
	size_t i;

	int mean = 0,
	    rem = 0;

	for (i = 0; i < N; i++) {
		int tmp = a[i] - mean;
		int ii = (int)i;
		mean += tmp / (ii + 1);
		rem += tmp % (ii + 1);

		if (abs(rem) > ii) {
			if (rem > 0) {
				rem -= ii + 1;
				mean++;
			}
			else {
				rem += ii + 1;
				mean--;
			}
		}
	}

	// округление до ближайшего целого
	//~ if (abs(rem) > ii / 2)
		//~ if (rem > 0)
			//~ mean++;
		//~ else
			//~ mean--;

	return mean;
}

int main(int argc, char *argv[])
{
	const size_t N = 88;

	int *a = (int *)malloc(N * sizeof(int));

	size_t i;
	for (i = 0; i < N; i++)
		a[i] = rand() % 1024;

	printf("avg(a[]) = %d\n", avg(N, a));

	free(a);

	return 0;
}