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#include<stdio.h>
#include<stdlib.h>
typedef struct treenode
{
    int data;
    struct node*left;
    struct node*right;    
}node;
void insert(node*,int);
void del();
 
int BT_add()
{
    node *root=(node*)malloc(sizeof(node));
    root=NULL;
    int select;
    int data;
    while(1)
    {
       printf("\n------------Select Work:----------\n");
       printf("(0)Exit\n(1)Insert(2)Del");
       scanf("%d",&select);     
       if(select==0)
	   printf("\n");
       break;
       switch(select)
       {
         case 1:          
             printf("Insert Data:");
             scanf("%d",&data);
             insert(root,data);
             break;
         case 2:
             del();
             break;  
       }       
    }
 
      system("pause");
      return 0; 
}
void insert(node*r,int data)
{
     node *newnode =(node*)malloc(sizeof(node)); 
     newnode->left = newnode->right =NULL;
     newnode->data = data;
     if(r==NULL)
     {
         r = newnode;  
     }
     else
     {
         newnode = r;
         if(data<=r->data)
         {
             return insert(newnode->left,data);           
         }
         else
         {
             return insert(newnode->right,data);
         }
     }
     printf("%d Insert Success",data);
}
void del()
{
 
}
 

prog.c: In function ‘BT_add’:
prog.c:22: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result
prog.c:30: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result
prog.c:39: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result
prog.c: In function ‘insert’:
prog.c:56: warning: passing argument 1 of ‘insert’ from incompatible pointer type
prog.c:60: warning: passing argument 1 of ‘insert’ from incompatible pointer type
/usr/lib/gcc/i686-pc-linux-gnu/4.3.4/../../../crt1.o: In function `_start':
(.text+0x18): undefined reference to `main'
collect2: ld returned 1 exit status

Standard output is empty