อธิบายยังไงครับ ขั้นตอนการทำงานมันครับ

#include <malloc.h>
#include <stdio.h>
#include <conio.h>
typedef struct TREE
{    
    int data;
    struct TREE *left;
    struct TREE *right;
    TREE;
}        
int main()
{        
    int data,depth;
    TREE *tree =NULL;
    TREE *InsertTree(int data,TREE *p);
    TREE *PrintTreeTriangle(TREE *tree, int level);
    int TreeDepth(TREE *tree,int *depth,int level);
    while(1)
    {    
        printf("\nKey to insert|");
        scanf("%d", &data);
        if (data==0)
        break;
        tree =InsertTree(data,tree);
        printf("\n Tree Display;\n");
        PrintTreeTriangle(tree,1);
        depth=0;
        TreeDepth(tree,&depth,0);
        printf("\nTree Depth =%d\n",depth);
    }    
    return(0);
}        
TREE *InsertTree(int data,TREE *p)
}        
    if(!p)
        {
        p=(TREE*)malloc(sizeof(TREE));      
        p->data=data;
        p->left=NULL;
        p->right=NULL;
        return(p);
        }
        if(data < p->data)
        p->left=InsertTree(data,p->left);
        else
        if(data > p->data)
        p->right=InsertTree(data,p->right);
        return(p);
}        
TREE *PrintTreeTriangle(TREE *tree, int level)
{        
    int i;
    if(tree)
    {
        PrintTreeTriangle(tree->right,level+1);    
        printf("\n\n");
        for(i=0;i<level;i++)
        printf("       ");
        printf("%d",tree->data);
        PrintTreeTriangle(tree->left,level+1);
    }    
    return(NULL);
}        
int TreeDepth(TREE *tree,int *depth,int level)
{
    if(tree)    
    {    
        if (level>*depth)
        *depth=level;
        TreeDepth(tree->left,depth,level+1);
        TreeDepth(tree->right,depth,level+1);
    }    
    return(0);
}