Question

Write a BCPL program that accepts strings from the user and builds them into a binary tree. Whenever the user types * as the input string, your program should print out the entire contents of the tree in alphabetical order, then delete the entire tree, starting again with an empty one.

Answer 1

The program is:

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

typedef struct def_nodo

{char num[500];

 struct def_nodo *izq, *der;

}Tiponodo;

void inserta(Tiponodo **insert, char i[]);

void borra(Tiponodo *p);

void imprime_orden(Tiponodo *p);

int main(void)

{

 char nombre[500];

 Tiponodo *raiz;

 raiz=NULL;

   do{printf("Give me the string you want: ");    

   __fpurge(stdin);

   gets(nombre);

inserta(&raiz,nombre);  

}while(strcmp(nombre,"*")!=0);

 imprime_orden(raiz);

   borra(raiz);

}

void inserta(Tiponodo **insert, char i[])//In this function we insert the new string in our tree

{Tiponodo *avanza, *nuevo;

 

 avanza=*insert;

 

     if((nuevo=(Tiponodo *)malloc(sizeof(Tiponodo)))==NULL)

{printf("no hay espacio libre");

  exit(1);

}

     strcpy(nuevo->num,i);

     

     nuevo->izq=NULL;

     nuevo->der=NULL;

     

     while(avanza!=NULL)

{

      if(strcmp(avanza->num,i)<0)

 {if(avanza->der!=NULL)

     avanza=avanza->der;

   else

     {avanza->der=nuevo;

       return;

     }

 }

      if(strcmp(avanza->num, i)>=0)

 {if(avanza->izq!=NULL)

     avanza=avanza->izq;

   else

     {avanza->izq=nuevo;

       return;

     }

 }  

 

}

     avanza=nuevo;

     *insert=avanza;

}

void imprime_orden(Tiponodo *p)//we use this function to print the tree

{if(p!=NULL)

   {imprime_orden(p->izq);

     printf("%s \n", p->num);

     imprime_orden(p->der);

   }

}

void borra(Tiponodo *p)//we use this function to delete the binary tree

{if(p!=NULL)

   {borra(p->izq);

     borra(p->der);

     free(p);

   }

}