Question

Java

Given the array, which has been converted to a linked list, I need to invoke
a remove method to remove a number from the list. The output for the first
array should come out like this
Now list1 = 24->18->3-7->null
Now list2 = 31->-9->5->21->4->0->8->null
Now lsit3 = 5->0->1->null

but i keep getting this output
Now list1= 12->3->7->null
Now list2= -7->null
Now list3= 5->0->1->null

int arr1[] = {24, 18, 12, 3, 7};
int arr2[] = {31, -9, 5, 21, 4, 0, 8, -7};
int arr3[] = {5, 5, 0, 1};

IntNode list1, list2, list3, list4, list5, list6;
list1 = createList(arr1);
list2 = createList(arr2);
list3 = createList(arr3);

System.out.println("to begin with, ");
System.out.println("list1= " + toString(list1));
System.out.println("list2= " + toString(list2));
System.out.println("list3= " + toString(list3));

list1 = remove(list1,12); // remove returns the new list so that list1 changes
list2 = remove(list2, -7); // invoke your method to remove -7 from list2
list3 = remove(list3, 5); // invoke your method to remove 5 from list3

  
System.out.println("Now list1= " + toString(list1));
System.out.println("Now list2= " + toString(list2));
System.out.println("Now list3= " + toString(list3));

So far my remove method looks like this:

public static IntNode remove(IntNode head,int value){
IntNode current = head;
IntNode prev = null;
if( current != null && current.data == value){
return head = current.next;
}
  
while( current != null && current.data != value){
//prev = current;
current = current.next;
}

prev = current;
return current;
}

Answer 1

Here is the corrected code:

public static IntNode remove(IntNode head,int value){
IntNode current = head;
IntNode prev = head;
  

//This condition is to check if head is itself the value
if(current != null && current.data == value){
return current.next;
}
  

//Iterating till we get the node.data = value
while(current != null && current.data != value){
prev = current;
current = current.next;
}
  

// If current node's data is equal to value

// then join the previous node's next to current node's next
if(current != null && current.data == value){
prev.next = current.next;
}
  
return head;
}

Hope it helps!