(2020年7月整理)数据结构课程设计哈夫曼编译器

1目哈夫曼编译器指导教师 学院信息科学与工程学院 2源代码………………12结点离根节点较近，权值较小的结点离根节点较远。法建立哈夫曼树时要进行多次选择，每次选择出权值最小和次小的两个节点,30，则走向左孩子，读到1，则走向右孩子。并将对应的子节点作为下一轮循环(1)建立哈夫曼树pfor(i=0;i<m;i++){tree[i]=newHuffmantree();}floatsmall1,small2;//建立哈夫曼树for(i=0;i<n;i++)//初始化叶节点，使每个叶结点都为独立的根节点{tree[i].parent=0;tree[i].lchild=-1;tree[i].rchild=-1;tree[i].weight=0;}for(i=0;i<n;i++)//将每种字符及其出现次数赋给叶节点，使每个叶节点对应一种字符{tree[i].ch=ch[i];tree[i].weight=arr[i];}for(i=n;i<m;i++)//由n个叶节点生成n-1个父节点{p1=0;p2=0;small1=10000;small2=100;for(j=0;j<i;j++)//选出权值最小与次小的两个节点if(tree[j].parent==0)4if(tree[j].weight<small1){small2=small1;small1=tree[j].weight;p2=p1;p1=j;}elseif(tree[j].weight<small2){small2=tree[j].weight;p2=j;}tree[p1].parent=i;//建立子节点与父节点间的对应关系，并将父节点权值赋为两子节点权值之和tree[p2].parent=i;tree[i].lchild=p1;tree[i].rchild=p2;tree[i].weight=tree[p1].weight+tree[p2].weight;}Code[]为定义在codetype类上的数组对象。intc,p;//编码部分，c为当前节点编号，p为其父节点编号Code=newCodetype[n];for(i=0;i<n;i++){Code[i]=newCodetype();Code[i].bits=newCharacter[n];}for(i=0;i<n;i++){Code[i].start=n;Code[i].ch=tree[i].ch;c=i;//start为编码位串的起始位置5p=tree[i].parent;while(p!=0){Code[i].start--;if(tree[p].lchild==c)//向上回溯编码Code[i].bits[Code[i].start]='0';elseCode[i].bits[Code[i].start]='1';c=p;p=tree[p].parent;}Code[i]=Code[i];//将父节点作为下一轮循环的子节点}(3)译码模块for(intq=0;q<t;q++){if(b[q]=='0')p=tree[p].lchild;elsep=tree[p].rchild;if(tree[p].lchild==-1){Stringym=tree[p].ch.toString();fw1.write(ym);p=m-1;}}(4)字符统计模块6for(inti=0;i<len;i++){//选出文章中每一种字符串for(intj=0;j<n;j++){if(a[i]==ch[j])break;elseif(j==n-1){ch[n-1]=a[i];//若ch[]中找不到a[i]中存放的字符，则将该种字符放到ch[]中。}}若找到，则说明该种字符已被存入ch[].break;}//初始化ch[],存放字符种类for(inti=0;i<len;i++)for(intj=0;j<n;j++){if(a[i]==ch[j])arr[j]++;//统计文章中每种字符的出现次数。}(5)Huffman类publicclassHuffmantree{publicintweight;publicintparent,lchild,rchild;//weight为节点的权值//分别为当前节点的父节点，左、右子节点编号publicCharacterch;//ch为节点名，即对应的字符。publicHuffmantree(){//初始化，每个节点构成一个单节点树，权值为0。weight=0;parent=0;lchild=-1;rchild=-1;ch='0';}(5)codetype类publicclassCodetype{publicCharacterbits[];//一维数组，存放每个字符对应的编码位串publicintstart;//start为每个字符位串的起始位置publiccharch;publicCodetype(){start=0;ch=0;}}}72.流程图1.su.fv,y,uewgbu;i;fewiu!2.WhenIwasalittlegirl,Idreamedtogrowup.BecauseIthinkachilddoesn'thasfreedom,andcan'tdoanythingbymyself.ButnowIhavegrowup,tomysurprise,Ifeelmoretiredandhavemoreresponsibility.ThoughIcandosomethingmyself,Idon'tfeelhappyatall.Ibelieveyoualsohavethesamethoughswithme.wheneveryuswasachild,wewantedtogrowup,butwhenwebecameaolderman,wedon'thavesuchnicelifeaswish.Sowhateverwearechildrenoradults,weshouldtrytomakeourlifebetter,andmakeourselvesmorehappy.weshouldtryourbesttostudy8hard,thenwecanletparentshavegoodlife,too!doourbesttodoourself!Believeyourself!Youarethebest!1.9体会通过本次实验，我复习了数据结构中常见的一种结构——树形结构，本次实件等操作上考虑不周，使程HuffmanepublicclassMain{publicstaticHuffmantreetreeblicstaticCodetypeCodepublicstaticvoidmain(String[]args)throwsException{ewcharFilefilenewFile"d:\\原文件.txt");leReaderfrnewFileReaderfilenewcharintfilelengthilenijnj}}Systemoutprintln;}}}n--;tree[i]=newHuffmantree();}floatsmallsmall哈夫曼树{}{}{p{}{}httreepweighttreepweight}wCodetypeneinewCodetypeeibitsnewCharactern}{eistartnCodeichtreei].ch;iparentwhilep=0){Code[i].start--;CodeibitsCodeistart'0';CodeibitsCodeistart'1';pparent}Codei}niSystemoutprintCodei].ch+":");forintrCodeistartrnr++)outprintCodeibitsrSystemoutprintln}FileWriterfwnewFileWriter"d:\\编码文件.txt");enklnlthCodelstarthnhgbmCodelbitshtoString}FilefilenewFile("d:\\编码文件.txt");FileReaderfrnewFileReaderfilechar[]b=newchar[(int)file1.length()];//将编码后的文件读入fr1.close();intt=b.length;p=m-1;//根节点FileWriterfw1=newFileWriter("d:\\译码文件.txt");for(intq=0;q<t;q++){if(b[q]=='0')p=tree[p].lchild;p=tree[p].rchild;if(tree[p].lchild==-1){gymtreepchtoStringp=m-1;}e}}publicclassHuffmantree{publicintweight;public