Print Immutable Linked List in Reverse in C++

Suppose we have an immutable linked list, we have to print out all values of each node in reverse with the help of the following interface −

• ImmutableListNode − This is an interface of an immutable linked list, we are given the head of the list.

We have to use the following functions to access the linked list −

• ImmutableListNode.printValue() − This will print value of the current node.

• ImmutableListNode.getNext() −This will return the next node.

So if the list is like: [0, -4, -1, 3, -5], then the output will be [-5, 3, -1, -4, 0]

To solve this, we will follow these steps −

• Define a stack st for ImmutableListNode type node

• while the head is not null

  • insert the head into st

  • head := next of head

• while st is not empty

  • print the value of stack top node

  • delete node from stack

Example (C++)

Let us see the following implementation to get a better understanding −

class Solution {
public:
   void printLinkedListInReverse(ImmutableListNode* head) {
      stack <ImmutableListNode*> st;
      while(head){
         st.push(head);
         head = head->getNext();
      }
      while(!st.empty()){
         st.top()->printValue();
         st.pop();
      }
   }
};

Input

[0,-4,-1,3,-5]

Output

[-5,3,-1,-4,0]