Recursion - Java - page 623

Answers to Self-Test Exercises
1. Hip Hip Hurray
2. public static void stars( int n)
{

System.out.print('*');
if (n > 1)
stars(n

− 1);

}

The following is also correct, but is more complicated:
3. public static void stars( int n)
{
if (n <= 1)
{
System.out.print('*');
}
else
{
stars(n − 1);

System.out.print('*');
}
}

public static void backward( int n)
{

if (n < 10)
{

System.out.print(n);

}
else
{

System.out.print(n%10); //write last digit
backward(n/10); //write the other digits backward

}

}

4. public static void writeUp( int n)
{
if (n >= 1)
{
writeUp(n − 1);

System.out.print(n + " "); //write while the
//recursion unwinds
}
}