If the input is like this ..
5 -> 9 -> 5 -> 5 -> 6 -> 6;
the output will be
5 -> 9 -> 5 -> 6
So there are 2 5's in the output Since the solution only compares the current element with the next one..
To avoid this follow this approach -->
List<Integer> nums = new ArrayList<>();
ListNode temp = A;
nums.add(A.val);
while(temp.next!=null){
if(nums.contains(temp.next.val)){
temp.next = temp.next.next;
}
else{
nums.add(temp.next.val);
temp = temp.next;
}
}
return A;