Epoch

題目

  Given an integer n, return the number of trailing zeroes in n!.

Initially, there is a Robot at position (0, 0). Given a sequence of its moves, judge if this robot makes a circle, which means it moves back to the original place.

The move sequence is represented by a string. And each move is represent by a character. The valid robot moves are  R  (Right).  L (Left), U (Up) and D (down). The output should be true or false representing whether the robot makes a circle.

題目

    Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.

題目

Given an integer array, find three numbers whose product is maximum and output the maximum product.

題目

Given an array of intergers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

題目

Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.

題目

題目

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

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.