Consider the following code.
public void printNumbers(int x, int y) {
if (x < 5) {
System.out.println("x: " + x);
}
if (y > 5) {
System.out.println("y: " + y);
}
int a = (int)(Math.random() * 10);
int b = (int)(Math.random() * 10);
if (x != y) printNumbers(a, b);
}
Which of the following conditions will cause recursion to stop with certainty?
A. x < 5
B. x < 5 or y > 5
C. x != y
D. x == y
Consider the following code.
public static int recur3(int n) {
if (n == 0) return 0;
if (n == 1) return 1;
if (n == 2) return 2;
return recur3(n - 1) + recur3(n - 2) + recur3(n - 3);
}
What value would be returned if this method were called and passed a value of 5?
A. 3
B. 9
C. 11
D. 16
Which of the following methods correctly calculates the value of a number x raised to the power of n using recursion?
A.
public static int pow(int x, int n) {
if (x == 0) return 1;
return x * pow(x, n);
}
B.
public static int pow(int x, int n) {
if (x == 0) return 1;
return x * pow(x, n - 1);
}
C.
public static int pow(int x, int n) {
if (n == 0) return 1;
return x * pow(x, n);
}
D.
public static int pow(int x, int n) {
if (n == 0) return 1;
return x * pow(x, n - 1);
}
Which of the following methods correctly calculates and returns the sum of all the digits in an integer using recursion?
A.
public int addDigits(int a) {
if (a == 0) return 0;
return a % 10 + addDigits(a / 10);
}
B.
public int addDigits(int a) {
if (a == 0) return 0;
return a / 10 + addDigits(a % 10);
}
C.
public int addDigits(int a) {
return a % 10 + addDigits(a / 10);
}
D.
public int addDigits(int a) {
return a / 10 + addDigits(a % 10);}
The intent of the following method is to find and return the index of the first ‘x’ character in a string. If this character is not found, -1 is returned.
public int findX(String s) {
return findX(s, 0);
}
Which of the following methods would make the best recursive helper method for this task?
A.
private int findX(String s) {
if (index >= s.length()) return -1;
else if (s.charAt(index) == 'x') return index;
else return findX(s);
}
B.
private int findX(String s, int index) {
if (index >= s.length()) return -1;
else return s.charAt(index);
}
C.
private int findX(String s, int index) {
if (index >= s.length()) return -1;
else if (s.charAt(index) == 'x') return index;
else return findX(s, index);
}
D.
private int findX(String s, int index) {
if (index >= s.length()) return -1;
else if (s.charAt(index) == 'x') return index;
else return findX(s, index + 1);
}