非线性结构之二叉树

本文主要是介绍非线性结构之二叉树，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

二叉树的建立和遍历

#include<stdio.h>
#include<malloc.h>
#include<string.h>

typedef struct tree{

   int data;
   struct tree *leftNode;
   struct tree *rightNode;
}tree;

tree * createTree();
void proTraversal(tree *root);
void InoTraversal(tree *root);
void posTraversal(tree *root);

int main()
{
   tree *root;
   root = createTree();
   printf("先序遍历：\n");
   proTraversal(root);
   printf("中序遍历：\n");
   InoTraversal(root);
   printf("后序遍历：\n");
   posTraversal(root);
   return 0;
}

tree * createTree()
{
   tree *root,*pn1,*pn2,*pn3,*pn4,*pn5,*pn6 = NULL;
   //存储节点
   root=(tree *)malloc(sizeof(tree));
   root->data = 0;
   pn1=(tree *)malloc(sizeof(tree));
   pn1->data = 1;
   pn2=(tree *)malloc(sizeof(tree));
   pn2->data = 2;
   pn3=(tree *)malloc(sizeof(tree));
   pn3->data = 3;
   pn4=(tree *)malloc(sizeof(tree));
   pn4->data = 4;
   pn5=(tree *)malloc(sizeof(tree));
   pn5->data = 5;
   pn6=(tree *)malloc(sizeof(tree));
   pn6->data = 6;
   //存储关系
   root->leftNode = pn1;
   root->rightNode = pn2;
   pn1->leftNode = pn3;
   pn1->rightNode = pn4;
   pn2->leftNode = pn5;
   pn2->rightNode = pn6;

   pn3->leftNode = NULL;
   pn3->rightNode = NULL;
   pn4->leftNode = NULL;
   pn4->rightNode = NULL;
   pn5->leftNode = NULL;
   pn5->rightNode = NULL;
   pn6->leftNode = NULL;
   pn6->rightNode = NULL;

   //返回头节点
   return root;
}

void proTraversal(tree *root)
{
   if(root!=NULL)
   {
       printf("%d\n",root->data);
       proTraversal(root->leftNode);
       proTraversal(root->rightNode);
   }
}

void InoTraversal(tree *root)
{
   if(root!=NULL)
   {
       InoTraversal(root->leftNode);
       printf("%d\n",root->data);
       InoTraversal(root->rightNode);
   }
}

void posTraversal(tree *root)
{
   if(root!=NULL)
   {
       posTraversal(root->leftNode);
       posTraversal(root->rightNode);
       printf("%d\n",root->data);
   }
}