Algoritmi - Somma particolare di elementi in un array

#define SIZE_ARR 5

int main()
{
	int rip[SIZE_ARR] = {1,2,3,3,3};
	int dat[SIZE_ARR] = {5,7,2,6,8};
	int sum[SIZE_ARR] = {0};
	int i, idx;

	for(i=0; i<SIZE_ARR; i++)
	{
		idx = rip[i];
		if(idx > 0) sum[idx-1] += dat[i];
	}

	for(i=0; i<SIZE_ARR; i++)
		printf("sum : %d\n", sum[i]);

	return 0;
}