Question

Get the file “HW4Part4a.java” from the repository. Modify the program class to match the new file name. Complete it by writing a recursive static int function named “pow2” with one parameter, an integer n. The function is defined as follows: if n ≤ 0 then pow2(n) = 1. Otherwise, pow2(n) = 2 · pow2(n − 1).

public class HW4Part4a {
	public static void main(String[] args) {
	for (int i = 0; i <= 20; i++) {
	System.out.println("pow2("+i+") = "+pow2(i));
	}
	}
	public static int pow2(int n) {
	/* replace this comment with your code */
	}
	}

Answer 1

ANSWER

Java code pasted below. The newly added code is shown in red colour.

public class HW4Part4a {
public static void main(String[] args) {
for (int i=0; i<=20; i++) {
System.out.println("pow2("+i+") = "+pow2(i));
}
}
public static int pow2(int n) {
if(n<=0)
return 1;
else
return (2*pow2(n-1));
}
}

Output Screen

D:\JavaSolutions>java HW4Part4a pow2(0) = 1 pow2(1) = 2 pow2(2) = 4 pow2(3) = 8 pow2(4) = 16 pow2(5) = 32 pow2(6) = 64 pow2 (7) = 128 pow2(8) = 256 pow2(9) = 512 pow2(10) = 1024 pow2(11) = 2048 pow2(12) = 4096 pow2(13) = 8192 pow2(14) = 16384 pow2(15) = 32768 pow2(16) = 65536 pow2(17) 131072 pow2 (18) = 262144 pow2(19) = 524288 pow2 (20) = 1048576