public static void main(String[] args) throws Exception {
List<Integer> currentLocation = Arrays.asList(0, 0);
Stream houses =
Files.lines(new File("input.txt").toPath())
.flatMap(line -> Stream.of(line.split("")))
.map(
s -> {
matchPath(s, currentLocation);
return new ArrayList<>(currentLocation);
})
.distinct();
System.out.println(houses.count());
List<Integer> santa = Arrays.asList(0, 0);
List<Integer> robot = Arrays.asList(0, 0);
List<String> paths =
Files.lines(new File("input.txt").toPath())
.flatMap(line -> Stream.of(line.split("")))
.collect(Collectors.toList());
Stream houses2 =
IntStream.range(0, paths.size())
.mapToObj(
i -> {
if (i % 2 == 0) {
matchPath(paths.get(i), santa);
} else {
matchPath(paths.get(i), robot);
}
return Arrays.asList(santa, robot);
})
.flatMap(lists -> Stream.of(lists.get(0), lists.get(1)))
.distinct();
System.out.println(houses2.count());
}
public void mainCollectorExample() {
Stream songsStream = getSongStream().map(s -> s.toUpperCase());
System.out.println(songsStream.count());
Set<String> setSongs = getSongStream().filter(s -> s.startsWith("it")).collect(toSet());
System.out.println("Set count:" + setSongs.size());
songsStream.close();
int sum = getSongStream().mapToInt(song -> song.toString().length()).sum();
System.out.println("sum is :" + sum);
// lets understand the difference between lazy and eager evaluation
getSongStream()
.filter(
song -> {
System.out.println("coming song in lazy:" + song);
return song.startsWith("al");
});
getSongStream()
.filter(
song -> {
System.out.println("coming song in eager:" + song);
return song.startsWith("al");
})
.count();
Stream<String> letters = Stream.of("b", "c", "d", null).filter(letter -> letter.isEmpty());
// Optional<String> firstLetter = Optional.of(letters.findFirst());
}
@Test
public void _04_서브스트림_추출() {
// limit
Stream<Double> randoms = Stream.generate(Math::random).limit(100);
assertThat(randoms.count(), is(100L));
// skip
Stream<String> words = Stream.of(contents.split("[\\P{L}]+")).skip(1);
assertThat(words.findFirst().get(), is("was"));
}
public static Matrix loadFromFile(File file) throws IOException {
BufferedReader reader = new BufferedReader(new FileReader(file));
int dimensionSize = 0;
Stream<String> lines = reader.lines();
int objectCount = (int) lines.count();
reader.close();
reader = new BufferedReader(new FileReader(file));
String[] temp = reader.readLine().split(" ");
double[][] objects = new double[objectCount][temp.length];
for (int i = 0; i < objectCount; i++) {
if (i != 0) temp = reader.readLine().split(" ");
for (int j = 0; j < temp.length; j++) {
objects[i][j] = Double.parseDouble(temp[j]);
}
}
reader.close();
return new Matrix(objects);
}
@Test
public void _04_스트림_결합() {
Stream<Character> combined = Stream.concat(characterStream("Hello"), characterStream("World"));
assertThat(combined.count(), is(10L));
}
