KTaNE Module Solver: Needy Knob (correction)

// I misunderstood the reference manual. I had to tweak the program to fix it.
// Module solver for Needy Knob (Keep Talking and Nobody Explodes)
// Call without arguments for usage help

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

#define SEQLEN (13)

#define HAS_SUBSTR(haystack, needle) \
    (  strstr( (haystack), (needle) ) != NULL \
    || strstr( (haystack) + SEQLEN, (needle) ) != NULL )

enum dir { UP, RIGHT, DOWN, LEFT, END };

char *data[END] = {
    "001011111101\000101010011011",
    "101111111010\000101100111010",
    "011001111101\000101010010001",
    "000010100111\000000010000110"
};

void
usage(void)
{
    puts("Usage: needyknob <string of [01]>");
    puts("Enter enough digits such that only one match is found\n");
    puts("1   2");
    puts("XXX XXX");
    puts("3   4");
    puts("XXX XXX\n");
    puts("Protip 1: you only need the first 9 digits.");
    puts(" 1   2");
    puts("[XXX XXX]");
    puts(" 3    4");
    puts("[XXX] ...\n");
    puts("Protip 2: If the defuser is having trouble understanding the order, try using the DONT DEAD OPEN INSIDE meme as an example.");
    puts("I.e. you don't want 'DONT DEAD OPEN INSIDE'; you want 'DONT OPEN DEAD INSIDE', or rather, 'DONT OPEN DEAD'.");
    exit(1);
}

int
main(int argc, char **argv)
{
    int nmatches = 0;
    int matches[END] = {0};

    if(argv[1] == NULL)
        usage();

    if(HAS_SUBSTR(data[UP], argv[1])){
        nmatches++;
        matches[UP] = 1;
    }

    if(HAS_SUBSTR(data[RIGHT], argv[1])){
        nmatches++;
        matches[RIGHT] = 1;
    }

    if(HAS_SUBSTR(data[DOWN], argv[1])){
        nmatches++;
        matches[DOWN] = 1;
    }

    if(HAS_SUBSTR(data[LEFT], argv[1])){
        nmatches++;
        matches[LEFT] = 1;
    }

    if(nmatches == 0)
        puts("[!] No matches found. Double check what you typed.");

    if(nmatches > 1)
        puts("[!] Found multiple matches. Need more digits.");

    matches[UP] && puts("Up.");
    matches[RIGHT] && puts("Right.");
    matches[DOWN] && puts("Down.");
    matches[LEFT] && puts("Left.");

    return 0;
}