二叉树

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
struct node
{
    char data;
    struct bitree *l,*r;
};
char a[55],b[55];//a前序b中序
int l1,h1,l2,h2;
struct node *creat() //前序建立
{
    struct node *root;
    char c;
    c = a[l1++];
    if(c == ',')
        return NULL;
    else
    {
        root = (struct node *)malloc(sizeof(struct node));
        root->data = c;
        root->l=creat();
        root->r=creat();
    }
    return root;
}
struct node *creat2(int n,char *a,char *b)//前序中序建立
{
    struct node *root;
    int i;
    if(n == 0)
        return NULL;
    root = (struct node *)malloc(sizeof(struct node));
    root->data=a[0];
    for(i = 0;i < n;i++)
    {
        if(b[i] == a[0])
            break;
    }
    root->l=creat2(i,a+1,b);
    root->r=creat2(n-i-1,a+i+1,b+i+1);
    return root;
}
struct node *creat3(int n,char *a,char *b)//中序后序建立
{
    struct node *root;
    int i;
    if(n == 0)
        return NULL;
    root = (struct node *)malloc(sizeof(struct node));
    root->data=b[n-1];
    for(i = 0;i < n;i++)
    {
        if(a[i] == b[n-1])
            break;
    }
    root->l=creat3(i,a,b);
    root->r=creat3(n-i-1,a+i+1,b+i);
    return root;
}
void preorder(struct node *root) //前序遍历
{
    struct node *p;
    p = root;
    if(p!=NULL)
    {
        printf("%c",p->data);
        preorder(p->l);
        preorder(p->r);
    }
}
void inorder(struct node *root)//中序遍历
{
    struct node *p;
    p = root;
    if(p!=NULL)
    {
        inorder(p->l);
        printf("%c",p->data);
        inorder(p->r);
    }
}
void postorder(struct node *root)//后序遍历
{
    struct node *p;
    p = root;
    if(p!=NULL)
    {
        postorder(p->l);
        postorder(p->r);
        printf("%c",p->data);
    }
}
int treehight(struct node *t) //二叉数高度
{
    int h,lh,rh;
    if(t == NULL)
    {
        h = 0;
    }
    else
    {
        lh = treehight(t->l);
        rh = treehight(t->r);
        if(lh>rh)
            h = lh+1;
        else
            h = rh+1;
    }
    return h;
}
int main()
{
    int n,t;
    scanf("%d",&t);
    while(t--)
    {
        struct node *root;
        scanf("%s%s",a,b);
        n = strlen(a);
        root = creat3(n,a,b);
        printf("%d\n",treehight(root));
    }
    return 0;
}