电大离散数学形成性考核作业5答案(图论部分).doc

形成性考核作业 姓 名： 学 号： 得 分： 教师签名： 电大离散数学作业5离散数学图论部分形成性考核书面作业本课程形成性考核书面作业共3次，内容主要分别是集合论部分、图论部分、数理逻辑部分的综合练习，基本上是按照考试的题型（除单项选择题外）安排练习题目，目的是通过综合性书面作业，使同学自己检验学习成果，找出掌握的薄弱知识点，重点复习，争取尽快掌握。本次形考书面作业是第二次作业，大家要认真及时地完成图论部分的综合练习作业。要求：将此作业用A4纸打印出来，手工书写答题，字迹工整，解答题要有解答过程，要求2010年12月5日前完成并上交任课教师（不收电子稿）。并在05任务界面下方点击“保存”和“交卷”按钮，以便教师评分。一、填空题1已知图G中有1个1度结点，2个2度结点，3个3度结点，4个4度结点，则G的边数是 15 2设给定图G(如右由图所示)，则图G的点割集是 f 3设G是一个图，结点集合为V，边集合为E，则G的结点 度数之和 等于边数的两倍4无向图G存在欧拉回路，当且仅当G连通且 等于出度 5设G=<V，E>是具有n个结点的简单图，若在G中每一对结点度数之和大于等于 n-1 ，则在G中存在一条汉密尔顿路 6若图G=<V, E>中具有一条汉密尔顿回路，则对于结点集V的每个非空子集S，在G中删除S中的所有结点得到的连通分支数为W，则S中结点数|S|与W满足的关系式为 W(G-V1) £½V1½ 7设完全图K有n个结点(n³2)，m条边，当 n为奇数 时，K中存在欧拉回路8结点数v与边数e满足 e=v-1 关系的无向连通图就是树9设图G是有6个结点的连通图，结点的总度数为18，则可从G中删去 4 条边后使之变成树10设正则5叉树的树叶数为17，则分支数为i = 5 二、判断说明题（判断下列各题，并说明理由）1如果图G是无向图，且其结点度数均为偶数，则图G存在一条欧拉回路(1) 不正确，缺了一个条件，图G应该是连通图，可以找出一个反例，比如图G是一个有孤立结点的图。2如下图所示的图G存在一条欧拉回路(2) 不正确，图中有奇数度结点，所以不存在是欧拉回路。3如下图所示的图G不是欧拉图而是汉密尔顿图 G 解：正确因为图中结点a，b，d，f的度数都为奇数，所以不是欧拉图。如果我们沿着(a,d,g,f,e,b,c,a)，这样除起点和终点是a外，我们经过每个点一次仅一次，所以存在一条汉密尔顿回路，是汉密尔顿图4设G是一个有7个结点16条边的连通图，则G为平面图解：(1) 错误假设图G是连通的平面图，根据定理，结点数v，边数为e，应满足e小于等于3v-6，但现在16小于等于3*7-6，显示不成立。所以假设错误。 5设G是一个连通平面图，且有6个结点11条边，则G有7个面(2) 正确根据欧拉定理，有v-e+r=2，边数v=11，结点数e=6，代入公式求出面数r=7三、计算题1设G=<V，E>，V= v1，v2，v3，v4，v5，E= (v1,v3)，(v2,v3)，(v2,v4)，(v3,v4)，(v3,v5)，(v4,v5) ，试(1) 给出G的图形表示； (2) 写出其邻接矩阵；(3) 求出每个结点的度数； (4) 画出其补图的图形解：(1)oooov1ov5v2v3v4(2) 邻接矩阵为(3) v1结点度数为1，v2结点度数为2，v3结点度数为3，v4结点度数为2，v5结点度数为2(4) 补图图形为oooov1ov5v2v3v42图G=<V, E>，其中V= a, b, c, d, e，E= (a, b), (a, c), (a, e), (b, d), (b, e), (c, e), (c, d), (d, e) ，对应边的权值依次为2、1、2、3、6、1、4及5，试（1）画出G的图形； （2）写出G的邻接矩阵；（3）求出G权最小的生成树及其权值（1）G的图形如下：（2）写出G的邻接矩阵（3）G权最小的生成树及其权值3已知带权图G如右图所示 (1) 求图G的最小生成树； (2)计算该生成树的权值解：(1) 最小生成树为12357(2) 该生成树的权值为(1+2+3+5+7)=184设有一组权为2, 3, 5, 7, 17, 31，试画出相应的最优二叉树，计算该最优二叉树的权35251071731173465权为 2*5+3*5+5*4+7*3+17*2+31=131四、证明题1设G是一个n阶无向简单图，n是大于等于3的奇数证明图G与它的补图中的奇数度顶点个数相等证明：设，则是由n阶无向完全图的边删去E所得到的所以对于任意结点，u在G和中的度数之和等于u在中的度数由于n是大于等于3的奇数，从而的每个结点都是偶数度的（度），于是若在G中是奇数度结点，则它在中也是奇数度结点故图G与它的补图中的奇数度结点个数相等2设连通图G有k个奇数度的结点，证明在图G中至少要添加条边才能使其成为欧拉图证明：由定理3.1.2，任何图中度数为奇数的结点必是偶数，可知k是偶数又根据定理4.1.1的推论，图G是欧拉图的充分必要条件是图G不含奇数度结点因此只要在每对奇数度结点之间各加一条边，使图G的所有结点的度数变为偶数，成为欧拉图故最少要加条边到图G才能使其成为欧拉图请您删除一下内容，O(_)O谢谢！【China's 10 must-see animations】The Chinese animation industry has seen considerable growth in the last several years. It went through a golden age in the late 1970s and 1980s when successively brilliant animation work was produced. Here are 10 must-see classics from China's animation outpouring that are not to be missed. Let's recall these colorful images that brought the country great joy. Calabash Brothers Calabash Brothers (Chinese: 葫芦娃) is a Chinese animation TV series produced by Shanghai Animation Film Studio. In the 1980s the series was one of the most popular animations in China. It was released at a point when the Chinese animation industry was in a relatively downed state compared to the rest of the international community. Still, the series was translated into 7 different languages. The episodes were produced with a vast amount of paper-cut animations. Black Cat Detective Black Cat Detective (Chinese: 黑猫警长) is a Chinese animation television series produced by the Shanghai Animation Film Studio. It is sometimes known as Mr. Black. The series was originally aired from 1984 to 1987. In June 2006, a rebroadcasting of the original series was announced. Critics bemoan the series' violence, and lack of suitability for children's education. Proponents of the show claim that it is merely for entertainment. Effendi "Effendi", meaning sir and teacher in Turkish, is the respectful name for people who own wisdom and knowledge. The hero's real name was Nasreddin. He was wise and witty and, more importantly, he had the courage to resist the exploitation of noblemen. He was also full of compassion and tried his best to help poor people. Adventure of Shuke and Beita【舒克与贝塔】 Adventure of Shuke and Beita (Chinese: 舒克和贝塔) is a classic animation by Zheng Yuanjie, who is known as King of Fairy Tales in China. Shuke and Beita are two mice who don't want to steal food like other mice. Shuke became a pilot and Beita became a tank driver, and the pair met accidentally and became good friends. Then they befriended a boy named Pipilu. With the help of PiPilu, they co-founded an airline named Shuke Beita Airlines to help other animals. Although there are only 13 episodes in this series, the content is very compact and attractive. The animation shows the preciousness of friendship and how people should be brave when facing difficulties. Even adults recalling this animation today can still feel touched by some scenes. Secrets of the Heavenly Book Secrets of the Heavenly Book, (Chinese: 天书奇谈) also referred to as "Legend of the Sealed Book" or "Tales about the Heavenly Book", was released in 1983. The film was produced with rigorous dubbing and fluid combination of music and vivid animations. The story is based on the classic literature "Ping Yao Zhuan", meaning "The Suppression of the Demons" by Feng Menglong. Yuangong, the deacon, opened the shrine and exposed the holy book to the human world. He carved the book's contents on the stone wall of a white cloud cave in the mountains. He was then punished with guarding the book for life by the jade emperor for breaking heaven's law. In order to pass this holy book to human beings, he would have to get by the antagonist fox. The whole animation is characterized by charming Chinese painting, including pavilions, ancient architecture, rippling streams and crowded markets, which fully demonstrate the unique beauty of China's natural scenery. Pleasant Goat and Big Big Wolf【喜洋洋与灰太狼】 Pleasant Goat and Big Big Wolf (Chinese:喜羊羊与灰太狼) is a Chinese animated television series. The show is about a group of goats living on the Green Pasture, and the story revolves around a clumsy wolf who wants to eat them. It is a popular domestic animation series and has been adapted into movies. Nezha Conquers the Dragon King（Chinese: 哪吒闹海） is an outstanding animation issued by the Ministry of Culture in 1979 and is based on an episode from the Chinese mythological novel "Fengshen Yanyi". A mother gave birth to a ball of flesh shaped like a lotus bud. The father, Li Jing, chopped open the ball, and beautiful boy, Nezha, sprung out. One day, when Nezha was seven years old, he went to the nearby seashore for a swim and killed the third son of the Dragon King who was persecuting local residents. The story primarily revolves around the Dragon King's feud with Nezha over his son's death. Through bravery and wit, Nezha finally broke into the underwater palace and successfully defeated him. The film shows various kinds of attractive sceneries and the traditional culture of China, such as spectacular mountains, elegant sea waves and exquisite ancient Chinese clothes. It has received a variety of awards. Havoc in Heaven The story of Havoc in Heaven（Chinese: 大闹天宫）is based on the earliest chapters of the classic story Journey to the West. The main character is Sun Wukong, aka the Monkey King, who rebels against the Jade Emperor of heaven. The stylized animation and drums and percussion accompaniment used in this film are heavily influenced by Beijing Opera traditions. The name of the movie became a colloquialism in the Chinese language to describe someone making a mess. Regardless that it was an animated film, it still became one of the most influential films in all of Asia. Countless cartoon adaptations that followed have reused the same classic story Journey to the West, yet many consider this 1964 iteration to be the most original, fitting and memorable, The Golden Monkey Defeats a Demon【金猴降妖】 The Golden Monkey Defeats a Demon (Chinese: 金猴降妖), also referred as "The Monkey King Conquers the Demon", is adapted from chapters of the Chinese classics "Journey to the West," or "Monkey" in the Western world. The five-episode animation series tells the story of Monkey King Sun Wukong, who followed Monk Xuan Zang's trip to the West to take the Buddhistic sutra. They met a white bone evil, and the evil transformed human appearances three times to seduce the monk. Twice Monkey King recognized it and brought it down. The monk was unable to recognize the monster and expelled Sun Wukong. Xuan Zang was then captured by the monster. Fortunately Bajie, another apprentice of Xuan Zang, escaped and persuaded the Monkey King to come rescue the monk. Finally, Sun kills the evil and saves Xuan Zang. The outstanding animation has received a variety of awards, including the 6th Hundred Flowers Festival Award and the Chicago International Children's Film Festival Award in 1989. McDull【麦兜】 McDull is a cartoon pig character that was created in Hong Kong by Alice Mak and Brian Tse. Although McDull made his first appearances as a supporting character in the McMug comics, McDull has since become a central character in his own right, attracting a huge following in Hong Kong. The first McDull movie McMug Story My Life as McDull documented his life and the relationship between him and his mother.The McMug Story My Life as McDull is also being translated into French and shown in France. In this version, Mak Bing is the mother of McDull, not his father. 6