Epoch

題目

  Given a roman numberal, convert it to an interger.

Question

  Given a binary tree, return the preorder traversal of its nodes' values.

問題

  Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magines; otherwise, it will return false.

題目

  Given a word, you need to judge whether the usage of capitals in it is right or not.

題目

  Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

Invert a binary tree

     4
   /   \
  2     7
 / \   / \
1   3 6   9

to

題目

  Given two binary trees, write a function to check if they are equal or not.

題目

  Given a binary tree, return the inorder traversal of its nodes' values.

問題

  Given an array `nums`, write a function to move all `0`'s to the end of it while maintaining the relative order of the non-zero elements.

題目

  Reverse a singly linked list