链接列表不包含大于特定数字的值

Question

How can I create a method that would check whether or not a linked list contains any number larger than a parameter?

Let's say we have the linked list

[ 8 7 1 3 ] . This would return true and

[ 10 12 3 2] would return false .

Would this work?

public boolean f(int k) {
    for (int=0; int<linkedList.size(); i++) {
        if (linkedList.get(i)>k)
            return false;
        }
        else
            return true;
    }

Also, I need to mention, this method would not change the list in any way and it should still work if the list contains null elements.

Thanks!

Answer 1

With Java 8

public boolean f(int k) {
   return !linkedList.stream().anyMatch(i-> i> k );
}

clarification : I assume that you want to return false from the method in the case that even a single element is higher then the given k . Hence I use anyMatch since we only need to look for one element that is higher. There is no need to loop over the whole list.

Answer 2

No this will not work how you have it currently. You need to loop through the whole list before returning. The only time you should return prematurely is if you find a reason to return false in this context. So move your return true outside of your loop and then you'd be fine.

Also, try to give meaning to your method and class definitions. Saying obj.f(12) doesn't really say much, whereas obj.noElementGreaterThan(12) says a lot more.

for example:

public boolean noElementGreaterThan( int k ) {
   for( int i = 0; i < linkedList.size(); i++ )
   {
      if( linkedList.get(i) > k )
         return false;
   }
   return true;
}

The reason this works is because it will loop through the entire list of objects, comparing each to the value passed in ( k ). If the value is greater than k , then it will return false , meaning in this case that it does have an element greater than k .

Answer 3

using streams you could do like this:

public boolean f(int k) {
    List<Integer> filtered = linkedList.stream().filter(i -> i >  k).collect(Collectors.toList());
    return !filtered.isEmpty();
}