wordPerms.c

wordPerms.c

#import <CoreFoundation/CoreFoundation.h>
#import <stdlib.h>

void PermutationsOfWord (CFMutableArrayRef output, CFStringRef prefix, CFStringRef letters);
CFStringRef CFStringCreateWithContentsOfFile (const char *path);

int main (int argc, const char *argv[]) {
	if (argc != 3) {
		printf("Usage: scrabblegen dictionary.txt setofletters\n");
		
		return EXIT_SUCCESS;
	}
	
	char dPath[PATH_MAX + 1];
	char *res = realpath(argv[1], dPath);
	
	if (!res) {
		printf("Invalid dictionary path!\n");
		
		return EXIT_FAILURE;
	}
	
	CFStringRef letters = CFStringCreateWithCString(NULL, argv[2], kCFStringEncodingUTF8);
	CFMutableArrayRef combinations = CFArrayCreateMutable(NULL, 0, NULL);
	
	PermutationsOfWord(combinations, CFSTR(""), letters);
	CFRelease(letters);
	
	// Sort the combinations so a parallel linear search can be done
	CFRange wholeRange = CFRangeMake(0, CFArrayGetCount(combinations));
	CFArraySortValues(combinations, wholeRange, (CFComparatorFunction) CFStringCompare, NULL);
	
	CFStringRef dictionary = CFStringCreateWithContentsOfFile(dPath);
	
	CFArrayRef lines = CFStringCreateArrayBySeparatingStrings(NULL, dictionary, CFSTR("\n"));
	CFRelease(dictionary);
	
	CFIndex currCombIdx = 0;
	CFIndex currLineIdx = 0;
	
	CFIndex linesLen = CFArrayGetCount(lines);
	CFIndex combsLen = CFArrayGetCount(combinations);
	
	printf("--\n");
	
	while (1) {
		CFStringRef line = CFArrayGetValueAtIndex(lines, currLineIdx);
		CFStringRef comb = CFArrayGetValueAtIndex(combinations, currCombIdx);
		
		CFComparisonResult res = CFStringCompare(line, comb, kCFCompareCaseInsensitive);
		
		if (res == kCFCompareLessThan) {
			currLineIdx++;
		}
		else if (res == kCFCompareEqualTo) {
			CFShow(line);
			
			currLineIdx++;
			currCombIdx++;
		}
		else {
			currCombIdx++;
		}
		
		if (currLineIdx == linesLen || currCombIdx == combsLen)
			break;
	}
	
	printf("--\n");
	
	CFRelease(lines);
	CFRelease(combinations);
	
	return 0;
}

void PermutationsOfWord (CFMutableArrayRef output, CFStringRef prefix, CFStringRef letters) {
	CFIndex len = CFStringGetLength(letters);
	
	for (int n = 0; n < len; n++) {
		UniChar c = CFStringGetCharacterAtIndex(letters, n);
		
		CFIndex pLen = CFStringGetLength(prefix);
		
		CFMutableStringRef nPrefix = CFStringCreateMutableCopy(NULL, pLen + 1, prefix);
		CFStringAppendCharacters(nPrefix, &c, 1);
		
		CFArrayAppendValue(output, nPrefix);
		
		if (len > 1) {
			CFMutableStringRef nLetters = CFStringCreateMutableCopy(NULL, len, letters);
			CFStringDelete(nLetters, CFRangeMake(n, 1));
			
			PermutationsOfWord(output, nPrefix, nLetters);
			CFRelease(nLetters);
		}
	}
}

/* Returns NULL if an error occured */
CFStringRef CFStringCreateWithContentsOfFile (const char *path) {
	FILE *file = fopen(path, "r");
	
	if (!file)
		return NULL;
	
	fseek(file, 0, SEEK_END);
	long size = ftell(file);
	rewind(file);
	
	char *buffer = (char *) malloc(sizeof(char) * size);
	
	if (!fread(buffer, 1, size, file))
		return NULL;
	
	fclose(file);
	
	CFStringRef str = CFStringCreateWithCString(NULL, buffer, kCFStringEncodingUTF8);
	free(buffer);
	
	return str;
}