Find non-intersecting binary triplets

threeand.c

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

void print_bin(uint32_t x)
{
	int i;
	for (i = 31; i >= 0; --i)
		putchar(x & (1 << i) ? '1' : '0');
}

int
main(void)
{
	size_t n;
	uint32_t *v;
	size_t i, j, k;
	int c;
	char buf[32];

	if (!scanf("%zu\n", &n)) {
		fprintf(stderr, "Could not read input size\n");
		return 1;
	} else if ((v = calloc(n, sizeof(*v))) == NULL) {
		fprintf(stderr, "Not enough memory\n");
		return 1;
	}

	for (i = 0; i < n;) {
		switch (c = getchar()) {
		case '0':
			v[i] = v[i] << 1;
			break;
		case '1':
			v[i] = (v[i] << 1) + 1;
			break;
		case EOF:
			fprintf(stderr, "Unexpected EOF\n");
			return 1;
		default:
			++i;
		}
	}

	for (i = 0 + 0; i < n; ++i) {
	for (j = i + 1; j < n; ++j) {
	for (k = j + 1; k < n; ++k) {
		if (!(v[i] & v[j] & v[k])) {
			print_bin(v[i]);
			putchar(' ');
			print_bin(v[j]);
			putchar(' ');
			print_bin(v[k]);
			putchar('\n');
		}
	}}}

	return 0;
}