输出二叉树第n个节点

#include<stdio.h>#include<stdlib.h>typedef struct BTNode{    struct BTNode *lchild,*rchild;    int data;}BTNode,*btnode;void createBtree(btnode &T){    int t;    scanf("%d",&t);    if(t==0)        T=NULL;    else    {        T=(btnode)malloc(sizeof(BTNode));        T->data=t;        createBtree(T->lchild);        createBtree(T->rchild);    }}int i=0;void trave(btnode &p,int n){    if(p)    {        i++;        if(i==n)        {            printf("the %dth node is %d\n",n,p->data);            return;        }        else        {            trave(p->lchild,n);            trave(p->rchild,n);        }    }}void main(){    btnode T;    int n;    createBtree(T);    printf("input n:");    scanf("%d",&n);    trave(T,n);}