二叉树的递归遍历

#include<stdio.h>

#include<stdlib.h>

struct TreeNode;

typedef struct TreeNode *Position;

typedef struct TreeNode *SearchTree;

SearchTree Insert(int x, SearchTree T);

struct TreeNode //结点声明

{

int data;

SearchTree left;

SearchTree right;

};

SearchTree Insert(int x, SearchTree T) //建立二叉树（插入结点的方法建立二叉树，小数在左，大数在右）

{

if(T==NULL){

T=malloc(sizeof(struct TreeNode));

T->data = x;

T->left = T->right =NULL;

}

else if(x < T->data)

T->left = Insert(x,T->left);

else if(x > T->data)

T->right = Insert(x,T->right);

return T;

}

void Zhongxu(SearchTree T) //中序遍历（因为特殊的创建方法，导致中序遍历输出为递增的数字）

{

if(T != NULL) {

Find(T->left);

printf("%5d",T->data);

Find(T->right);

}

}

void Xianxu(SearchTree T) //先序遍历

{

if(T != NULL){

printf("%5d",T->data);

Xianxu(T->left);

Xianxu(T->right);

}

}

void Houxu(SearchTree T) //后序遍历

{

if(T != NULL){

Houxu(T->left);

Houxu(T->right);

printf("%5d",T->data);

}

}

int main()

{

SearchTree T=NULL;

int x;

printf("请输入根结点： ");

scanf("%d", &x);

while(x != -1) {

T = Insert(x,T);

printf("请输入值： ");

scanf("%d", &x);

}

printf("先序: ");

Xianxu(T);

printf("\n");

printf("中序: ");

Zhongxu(T);

printf("\n");

printf("后序: ");

Houxu(T);

printf("\n");

}