unique-value

Question

given a head of a linked list return a boolean indicating whether there exists exactly one unique value.

input:

Link 1

Link 2

Output:

FALSE

TRUE

Solution

we can solve this using a set or a variable to hold the first value of our head, and check if all the nodes in the list contain exactly the same value, if not we can simply return false.

Javascript

const isUniqueValueList = (head) => {
  // todo
  const set = new Set();
  set.add(head.val);
  while (head !== null) {
    if (!set.has(head.val)) {
      return false;
    }
    head = head.next;
  }
  return true;
};

Java

Concepts

• Linked List
• Single Linked List

Patterns

• Map/Set