圣诞树显示不正确

Question

问题是星星不会形成圣诞树，它们只是形成一个直角三角形。 如何解决？ https://i.imgur.com/vKpxRhP.png https://i.imgur.com/eyuccNn.png

public static void main(String[] args) throws FileNotFoundException {
    File file = new File("In0103.txt");
    Scanner in = new Scanner(file);
    int maxWidth = in.nextInt();
    int initialWidth = 1;
    int initialLevel = 1;
    int maxLevel = (maxWidth + 1) / 2;
    int freeSpace = maxLevel - 1;

    printChristmasTree(initialWidth, initialLevel, maxLevel, freeSpace, null);
}

static void printChristmasTree(int width, int level, int maxLevel, int freeSpace, PrintWriter save) throws FileNotFoundException {
    if (save == null) {
        save = new PrintWriter("Out0103.txt");
    }
    if (level < maxLevel) {
        save.println(Stream.generate(() -> " ").limit(freeSpace).collect(Collectors.joining()));
        save.println(Stream.generate(() -> "*").limit(width).collect(Collectors.joining()));
        save.println();
        printChristmasTree(width = width + 2, ++level, maxLevel, --freeSpace, save);
    } else {
        save.println(Stream.generate(() -> " ").limit(freeSpace).collect(Collectors.joining()));
        save.println(Stream.generate(() -> "*").limit(width).collect(Collectors.joining()));
        save.close();
    }

}

Answer 1

你几乎明白了。但是您正在使用save.println() 打印freeSpace，但您不需要换行，只需save.print()。此外，还有一个额外的save.println() 也不需要：

public static void main(String[] args) throws FileNotFoundException {
    File file = new File("In0103.txt");
    Scanner in = new Scanner(file);
    int maxWidth = in.nextInt();
    int initialWidth = 1;
    int initialLevel = 1;
    int maxLevel = (maxWidth + 1) / 2;
    int freeSpace = maxLevel - 1;

    printChristmasTree(maxWidth, initialWidth, initialLevel, maxLevel, freeSpace, null);
}

static void printChristmasTree(int maxWidth, int width, int level, int maxLevel, int freeSpace, PrintWriter save) throws FileNotFoundException {
    if (save == null) {
        save = new PrintWriter("Out0103.txt");
        save.println("n =" + maxWidth + "");
    }

    if (level < maxLevel) {
        save.print(Stream.generate(() -> " ").limit(freeSpace).collect(Collectors.joining()));
        save.println(Stream.generate(() -> "*").limit(width).collect(Collectors.joining()));
        printChristmasTree(maxWidth, width + 2, ++level, maxLevel, --freeSpace, save);
    } else {
        save.print(Stream.generate(() -> " ").limit(freeSpace).collect(Collectors.joining()));
        save.println(Stream.generate(() -> "*").limit(width).collect(Collectors.joining()));
        save.close();
    }
}

也许您需要将行从 int freeSpace = maxLevel - 1; 更改为 int freeSpace = maxLevel;，因为您的树的最后一行似乎有一个空闲空间。