Data structure Binary tree operations (C language)

    //二叉树操作
    #include"stdio.h"
    #include"stdlib.h"
    
    typedef struct node{
    	char data;
    	struct node *lchild,*rchild;	
    }bintnode;
    
    typedef bintnode *bintree;
     
    
    typedef struct stack
    {
    	bintree data[100];
    	int tag[100];
    	int top;
    }stack;
    
    //压栈 
    void push(stack *s, bintree t)
    {
    	s->data[s->top]=t;
    	s->top++;
    }
    
    //出栈
    bintree pop(stack *s)
    {
    	if(s->top!=0)
    	{
    		s->top--;
    		return (s->data[s->top]);
    	}
    	else
    	return NULL;
    } 
    
    //创建（前序） 
    bintree cr