Question

• swapArrayEnds(int[] nums): swaps the first and last elements of its array parameter. Ex: {10, 20, 30, 40} becomes {40, 20, 30, 10}.
• removeTen(int[] nums): returns a version of the given array where all the 10's have been removed. The remaining elements should shift left towards the start of the array as needed, and the empty spaces at the end of the array should be set to 0. Ex: {1, 10, 10, 2} yields {1, 2, 0, 0}. You can make a new array and return the new array.

Note that swapArrayEnds() does not need to return the result, as it makes changes to the array referenced by the parameter, which is the same array reference by the argument. On the other hand, removeTen() does not direct make changes to the array, but creates a new array, which requires to be made.

• Java passes parameter by value, a method cannot change the actual argument. However, a method can make changes to the object that is referenced by the argument.
• If a method changes the array's contents, the method usually has a void return type.
• If the method does not change the array's contents, but create a new array, then the method needs to return the newly created array.

public class RemoveTen {
public static void main(String[] args) {
int[] nums = {1, 10, 10, 2};
  
swapArrayEnds(nums);

for(int i = 0; i < nums.length; i++)
System.out.print(nums[i] + " ");

int[] result = removeTen(nums);
  
for(int i = 0; i < result.length; i++)
System.out.print(result[i] + " ");
System.out.println();

for(int i = 0; i < nums.length; i++)
System.out.print(nums[i] + " ");
System.out.println();
}

public static void swapArrayEnds(int[] nums) {
/*FIXME Complete the implementation of the swapArrayEnds method*/
  
}

public static int[] removeTen(int[] nums) {
/*FIXME Complete the implementation of the removeTen method*/
  
}

  
}

Answer 1

public class RemoveTen {

public static void main(String[] args) {

int[] nums = {1, 10, 10, 2};

swapArrayEnds(nums);

for(int i = 0; i < nums.length; i++)

System.out.print(nums[i] + " ");

System.out.println();

int[] result = removeTen(nums);

for(int i = 0; i < result.length; i++)

System.out.print(result[i] + " ");

System.out.println();

for(int i = 0; i < nums.length; i++)

System.out.print(nums[i] + " ");

System.out.println();

}

public static void swapArrayEnds(int[] nums) {

int temp=nums[0];

nums[0]=nums[nums.length-1];

nums[nums.length-1]=temp;

}

public static int[] removeTen(int[] nums) {

int new_array[]=new int[nums.length];

int k=0;

for(int i=0;i<nums.length;i++)

{

if(nums[i]!=10)

new_array[k++]=nums[i];

}

if(k<nums.length)

for(int i=k;i<nums.length;i++)

new_array[i]=0;

return new_array;

}

}