Given a Linked List of integers. The task is to write a program to modify the linked list such that all even numbers appear before all the odd numbers in the modified linked list. It is not needed to keep the order of even and odd nodes same as that of the original list, the task is just to rearrange the nodes such that all even valued nodes appear before the odd valued nodes.
Input: 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> 8 -> 9 -> 10 -> NULL
Output: 10 -> 8 -> 6 -> 4 -> 2 -> 1 -> 3 -> 5 -> 7 -> 9 -> NULL
Input: 4 -> 3 -> 2 -> 1 -> NULL
Output: 2 -> 4 -> 3 -> 1 -> NULL
The idea is to iteratively push all the elements of the linked list to deque as per the below conditions:
- Start traversing the linked list and if an element is even then push it to the front of the Deque and,
- If the element is odd then push it to the back of the Deque.
Finally, replace all elements of the linked list with the elements of Deque starting from the first element.
Below is the implementation of the above approach:
Given linked list: 1 2 3 4 5 6 7 8 9 10 After rearrangement: 10 8 6 4 2 1 3 5 7 9
Time complexity: O(N)
Auxiliary Space: O(N), where N is the total number of nodes in the linked list.
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- deque::at() and deque::swap() in C++ STL
- deque::pop_front() and deque::pop_back() in C++ STL
- deque::front() and deque::back() in C++ STL
- deque::empty() and deque::size() in C++ STL
- deque::clear() and deque::erase() in C++ STL
- deque::operator= and deque::operator in C++ STL
- deque::begin() and deque::end in C++ STL
- deque::emplace_front() and deque::emplace_back() in C++ STL
- Implementation of Deque using doubly linked list
- Implement Stack and Queue using Deque
- Sum and Product of all Fibonacci Nodes of a Singly Linked List
- Reverse even elements in a Linked List
- Implementation of Deque using circular array
- Circular rotation of an array using deque in C++
- Level order traversal in spiral form | Using Deque
- Reverse nodes of a linked list without affecting the special characters
- Bubble Sort for Linked List by Swapping nodes
- Maximum sum of K consecutive nodes in the given Linked List
- Find the string formed by joining k consecutive nodes of linked list
- Deque | Set 1 (Introduction and Applications)
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