Climbing Stairs
rev
 Given a string containing just the characters
    '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
    The brackets must close in the correct order, "()" and "()[]{}" are all
    valid but "(]" and "([)]" are not.
Given a string s and a dictionary of words dict, determine if s can be
  segmented into a space-separated sequence of one or more dictionary words.
  For example, given
  s = "leetcode",
  dict = ["leet", "code"].
  Return true because "leetcode" can be segmented as "leet code".