gistfile1.m

NSString* truncateString(NSString* input)
{
	NSCountedSet* set = [[NSCountedSet alloc] init];
	for( int i = 0; i < [input length]; i++ ){
		[set addObject:[NSString stringWithFormat:@"%c", [input characterAtIndex:i]]];
	}
	NSMutableString* result = [[NSMutableString alloc] init];
	for( NSString* key in set ){
		[result appendString:key];
		if( [set countForObject:key] > 1 ){
			[result appendString:key];
		}
	}
	
	[set release];
	
	return [result autorelease];
}