Split X into N uniformly-distributed pieces (C)

split.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>

int* split(int n, int numPieces);
int randInt(int min, int max);
int sumList(int* list, int size);
void printList(int* list, int size);
void seedrand();

int main(int argc, char* argv[]) {
	int n = atoi(argv[1]);
	int numPieces = atoi(argv[2]);

	int* list = split(n, numPieces);
	int sum = sumList(list, numPieces);

	printf("sum: %d\n", sum);
	printList(list, numPieces);

	free(list);
	
	return 0;
}

int* split(int n, int numPieces) {
	seedrand();

	int* rtn = (int*) malloc(numPieces * sizeof(int));

	int mid = n / numPieces;
	int delta = 0;

	for (int i = 0; i < numPieces; i++) {
		if (i % 2 == 0) {
			delta = randInt(0, mid);
		} else {
			delta = -delta;
		}

		if (numPieces % 2 != 0 && i == numPieces - 1) {
			delta = 0;
		}

		rtn[i] = mid + delta;
	}

	int sum = sumList(rtn, numPieces);
	int diff;

	if (sum > n) {
		diff = n - sum;
	} else {
		diff = sum - n;
	}

	if (diff != 0) {
		for (int i = 0; i < abs(diff); i++) {
			int index = randInt(0, numPieces - 1);

			if (diff > 0) {
				rtn[i] -= 1;
			} else {
				rtn[i] += 1;			
			}
		}
	}

	return rtn;
}

int randInt(int min, int max) {
	return rand() / (RAND_MAX / (min - max + 1) + 1);
}

int sumList(int* list, int size) {
	int total = 0;
	for (int i = 0; i < size; i++) {
		total += list[i];
	}

	return total;
}

void printList(int* list, int size) {
	printf("[ ");

	for (int i = 0; i < size; i++) {
		printf("%d", list[i]);

		if (i != size - 1) {
			printf(", ");
		}
	}

	printf(" ]\n");
}

void seedrand() {
	struct timeval tv;
  	struct timezone tz;
  	struct tm *tm;

  	gettimeofday (&tv, &tz);
  	tm = localtime (&tv.tv_sec);
  	srand (tv.tv_usec);
}