递归 实例 english ruler

public static void drawRuler(int length, int tick) {
    drawLine(tick, 0);
    for (int i = 1; i <= length; i++) {
        drawInterval(tick - 1);
        drawLine(tick, i);
    }
}

private static void drawLine(int tickNum, int num) {
    for (int i = 0; i < tickNum; i++) {
        System.out.print("- ");
    }
    if (num >= 0) {
        System.out.println(num);
    } else {
        System.out.println();
    }

}

private static void drawInterval(int centralTick) {
    if (centralTick == 1) {
        drawLine(centralTick, -1);
    } else {
        drawInterval(centralTick - 1);
        drawLine(centralTick, -1);
        drawInterval(centralTick - 1);
    }
}