Question

public static int[] collatz(int start, int numIterations)

Given integer start and integer numIterations, return an array containing the Collatz sequence beginning with start up to numIterations. The Collatz function is defined by: 3n + 1 if n is odd n/2 if n is even Given start = 7 and numIterations = 3, this method returns [7, 22, 11, 34]

TESTING:

collatz(7,3) should return {7, 22, 11, 34}

collatz(6,0) should return {6}

collatz(6, 5) should return {6, 3, 10, 5, 16, 8}

collatz(1,1) should return {1, 4}

collatz(0, 5) should return {0, 0, 0, 0, 0, 0}

Parameters:

start - starting integer

numIterations - how long to compute the Collatz sequence for

Returns:

an array containing the Collatz sequence beginning with start up to numIterations.

CODE I HAVE THAT IS WRONG:

public class Collatz {

public void main(String[] args) {

int arr[]=collatz(7, 3);

for(int x:arr)

System.out.print(x+" ");

}

public int[] collatz(int start, int numIterations) {

int arr[] = new int[numIterations + 1];

arr[0]=start;

for (int i = 1; i < 4; i++) {

if(start%2==1)

start=start*3+1;

else

start=start/2;

arr[i]=start;

}

return arr;

}

}

Answer 1

public class Collatz {

public static void main(String[] args) {

int[] arr=collatz(6, 5);

for(int x:arr)

System.out.print(x+" ");

}

public static int[] collatz(int start, int numIterations) {

int[] arr = new int[numIterations + 1];

arr[0]=start;

for (int i = 1; i <= numIterations; i++) {

if(start%2==1)

start=start*3+1;

else

start=start/2;

arr[i]=start;

}

return arr;

}

}