Abstract computer graphics is nearly 20 areas of science and technology to achieve another important achievements， As is the computer and its peripherals and the emergence and development It is modern computer science with the radar， television and image processing technology convergence and the development of the In shipbuilding， aerospace， automotive， electronics， machinery， civil engineering， television advertising， geographic information， Textile Industry wide field of application， which contributed to the discipline continues to develop， and the application to resolve the various new issues and further enrich this subject Arise soon， in order to plotters and cathode ray tube output graphics on the screen， computer graphics attendant was Now， it has to object to the development of the model and graphics creation， access and management of new Computer Graphics (Computer Graphics) is to study how to use digital computer generated， Graphics processing and display of a Graphics specific wide range of applications， from basic technology can handle only two categories of lines， such as engineering drawings， maps， charts curve; Others are shaded maps， photographs and To generate the graphics， there must first of all raw data and mathematical models， such as the idea of the engineering staff draft Aerial topographical interpretation of data， the overall program model， business statistics on the information and so These figures after the importation of processed into computer graphics Now the computer can generate very complex graphics， but the graphics， no matter how complex， It is by the basic combination of Therefore， the learning of basic graphics master algorithm is the basis of computer This paper introduces the C # language generation line of three algorithms : numerical differential Act (DDA) China Midpoint method and Bresenham algorithm， and then explain the midpoint drawcircle algorithm， polygon generation 你可以在网上找一些在线翻译软件，我是用Google翻译的。
翻译成英文：Discuss with variable span and the constraints of X pattern matching problem， which extends therange of variable span effect of wildcards， X condition defines a matching number of textcharacters， forming a large and sparse candidate solution Description through the form， the input text， patterns and variable span is transformed into a directed acyclic graph structure， and prove that the graph structure in the path from the top layer to the bottom layer which is a collection of candidate solution space， the path subset independent of each other as the matching solution Then we give a graph structure of the path search Algorithm alternately pruning and search， use the preorder traversal delete redundant nodes， and according to the node's locationinformation and share information to choose the The experimental part adopts the matchingloss rate metrics of the completeness of the solution set of the solution， the results show that the algorithm with the heuristic algorithm can be complementary， effectively reduce the matching solution loss
