非线性结构之二叉树

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);

}

}