線上 高中程式解題系統 An Online Judge System For Beginners
線上 高中程式解題系統 An Online Judge System For Beginners
http://zerojudge.tw/Problems
較新的文章
較舊的文章
首頁
Biodiversity
Clash Royale CLAN TAG #URR8PPP Variety and variabiity of life forms A sampling of fungi collected during summer 2008 in Northern Saskatchewan mixed woods, near LaRonge is an example regarding the species diversity of fungi. In this photo, there are also leaf lichens and mosses. Biodiversity refers to the variety and variability of life on Earth. Biodiversity typically measures variation at the genetic, species, and ecosystem level. [1] Terrestrial biodiversity is usually greater near the equator, [2] which is the result of the warm climate and high primary productivity. [3] Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species. [4] Marine biodiversity is usually highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal g...
2
意見
林隆山
提到... @
2015年10月22日 上午4:34
作者已經移除這則留言。
林隆山
提到... @
2015年10月22日 上午4:36
大家好,小弟有幾個問題想麻煩板上高手們替小弟解惑,謝謝
1.Write down the regular expressions for the following languages,and explain your idea:
(a) L={ w | w has no substring "ab"}, ∑ = {a,b}
(b) L={ w | ||w||=3n+2}
(c) L={ w | w contains an even number of a}
2.Prove that the following languages are NOT regular by using closure propertiesand pumping lemma.
Please give formal proofs based on the pumping theory
(a) L={a^nbbba^n}
(b) L={a^nb ,n=k^2 -1}
(c) L={w=w^R}
張貼留言