Write a function to check if a Singly linked list is a palindrome or not. For example, the linked list

2 -> 3 -> 4 -> 5 -> 4 -> 3 -> 2 | is a palindrome |

M -> A -> L -> A-> Y -> A -> L -> A -> M | is a palindrome |

2 -> 3 -> 4 -> 5 -> 4 -> 6 -> 2 | is NOT a palindrome |

K -> A -> M -> A -> L | is NOT a palindrome |

The function should take O(n) time in worst case. Continue reading »