pretree.c

来自「《数据结构》教材源程序,可以让你轻松的根据教材学习数据结构」· C语言 代码 · 共 41 行

#include <stdio.h>
#define m 3
typedef char datatype;
typedef struct node {
     datatype data;
     struct node *child[m];
} node,*tree;
void createtree(tree *p)
 {/*按前序遍历顺序建立一棵3度树的递归算法*/
   
   int i; char ch;
   
   if ((ch=getchar())==' ')  *p=NULL;
   else
      {
	 *p=(tree) malloc (sizeof(node));
	 (*p)->data=ch;
	 for (i=0;i<m;++i)
	   createtree(&(*p)->child[i]);
      }
     
   }

void preorder(tree p)
 {/*树的前序遍历*/
   int i;
   if (p!=NULL)
     {
       printf("%c",p->data);
       for (i=0;i<m;++i)
	  preorder(p->child[i]);
       }
 }
main()
 {
   tree t;
   printf("please input the preorder sequence of the tree:\n");
   createtree(&t);
   printf("\nthe preorder is:");
   preorder(t);
   }