赫夫曼树C语言代码实现（最小二叉树）

#include <stdio.h> #include <string.h> #include <stdlib.h> #include <malloc.h> #include <conio.h> typedef struct { unsigned int weight; unsigned int parent,lchild,rchild; }HTNode,*HuffmanTree; typedef char **HuffmanCode; typedef struct { unsigned int s1; unsigned int s2; } MinCode; void Error(char *message); HuffmanCode HuffmanCoding(HuffmanTree HT,HuffmanCode HC,unsigned int *w,unsigned int n); MinCode Select(HuffmanTree HT,unsigned int n); void Error(char *message) { fprintf(stderr,"Error:%s\n",message); exit(1); } HuffmanCode HuffmanCoding(HuffmanTree HT,HuffmanCode HC,unsigned int *w,unsigned int n) { unsigned int i,s1=0,s2=0; HuffmanTree p; char *cd; unsigned int f,c,start,m; MinCode min; if(n<=1) Error("Code too small!"); m=2*n-1; HT=(HuffmanTree)malloc((m+1)*sizeof(HTNode)); for(p=HT,i=0;i<=n;i++,p++,w++) { p->weight=*w; p->parent=0; p->lchild=0; p->rchild=0; } for(;i<=m;i++,p++) { p->weight=0; p->parent=0; p->lchild=0; p->rchild=0; } for(i=n+1;i<=m;i++) { min=Select(HT,i-1); s1=min.s1; s2=min.s2; HT[s1].parent=i; HT[s2].parent=i; HT[i].lchild=s1; HT[i].rchild=s2; HT[i].weight=HT[s1].weight+HT[s2].weight; } printf("哈夫曼表:\n"); printf("结点Number\t权重weight\t双亲parent\t左孩儿lchild\t右孩儿rchild\n"); for(i=1;i<=m;i++) printf("%d\t\t%d\t\t%d\t\t%d\t\t%d\n",i,HT[i].weight,HT[i].parent,HT[i].lchild,HT[i].rchild); HC=(HuffmanCode)malloc((n+1)*sizeof(char *)); cd=(char *)malloc(n*sizeof(char *)); cd[n-1]='\0'; for(i=1;i<=n;i++) { start=n-1; for(c=i,f=HT[i].parent;f!=0;c=f,f=HT[f].parent) if(HT[f].lchild==c) cd[--start]='0'; else cd[--start]='1'; HC[i]=(char *)malloc((n-start)*sizeof(char *)); strcpy(HC[i],&cd[start]); } free(cd); return HC; } MinCode Select(HuffmanTree HT,unsigned int n) { unsigned int min,secmin; unsigned int temp; unsigned int i,s1,s2,tempi; MinCode code; s1=1;s2=1; for(i=1;i<=n;i++) if(HT[i].parent==0) { min=HT[i].weight; s1=i; break; } tempi=i++; for(;i<=n;i++) if(HT[i].weight<min&&HT[i].parent==0) { min=HT[i].weight; s1=i; } for(i=tempi;i<=n;i++) if(HT[i].parent==0&&i!=s1) { secmin=HT[i].weight; s2=i; break; } for(i=1;i<=n;i++) if(HT[i].weight<secmin&&i!=s1&&HT[i].parent==0) { secmin=HT[i].weight; s2=i; } if(s1>s2) { temp=s1; s1=s2; s2=temp; } code.s1=s1; code.s2=s2; return code; } void main() { HuffmanTree HT=NULL; HuffmanCode HC=NULL; unsigned int *w=NULL; unsigned int i,n; printf("请输入结点个数n:\n"); scanf("%d",&n); w=(unsigned int *)malloc((n+1)*sizeof(unsigned int *)); w[0]=0; printf("输入各结点相应的权重weight:\n"); for(i=1;i<=n;i++) { printf("第%d个结点w[%d]=",i,i); scanf("%d",&w[i]); } HC=HuffmanCoding(HT,HC,w,n); printf("哈夫曼编码:\n"); printf("结点Number\t权重Weight\t编码Code\n"); for(i=1;i<=n;i++) printf("%d\t\t%d\t\t%s\n",i,w[i],HC[i]); }