Error when executing the program hangs. Circular list(Solved) However I’m still in doubt

Question

I have an error that only appears during the execution of the program. I would like someone who has knowledge of why this occurs, can explain to me.

#include<stdio.h>
#include<stdlib.h>

struct TNoDeCaractere
{
char caractere;
struct TNoDeCaractere *proximo;
};

 struct TNoDeCaractere* inicio;

void insere(char valor){
struct TNoDeCaractere *p, *np;

//Se a lista está vazia, cria um nó e faz "inicio"apontar para ele.
if(inicio == NULL){

np=malloc(sizeof(struct TNoDeCaractere));
(*np).caractere= valor;
(*np).proximo =inicio;
inicio=np;

}else{//Caso contrário, ou seja, se a lista não está vazia...
p=malloc(sizeof(struct TNoDeCaractere));
p=inicio;
//varre toda a lista,
while((*p).proximo !=inicio){
p=(*p).proximo;
}printf("Teste");
//Cria novo nó
np=malloc(sizeof(struct TNoDeCaractere));
(*np).caractere=valor;
(*np).proximo=inicio;
// e liga a lista existente ao novo nó.
(*p).proximo=np;
}
}
void imprimir(){
struct TNoDeCaractere *p;
p=inicio;
while((*p).proximo !=NULL){
   printf("Valor: %d \n",(*p).proximo);
    p=(*p).proximo;
}
}
 void remover(char valor)
{
struct TNoDeCaractere *pAnt, *p;
//Verifica se a partir do segundo nó, há nó a ser retirado.
pAnt=inicio;
p=(*inicio).proximo;
while(p!=inicio)
    {
        if((*p).caractere == valor)
        {

            (*pAnt).proximo=(*p).proximo;free(p);
            p=(*pAnt).proximo;
        }else{
            pAnt=(*pAnt).proximo;
            p=(*p).proximo;
            }
    }//Testa se a lista estácom o valor aser retirado no primeiro nó
    if((*inicio).caractere == valor)
    {

        p=(*inicio).proximo;
        free(inicio);
        inicio=p;
    }

}




int main(){

inicio=NULL;


insere("a");

insere("c");
insere("b");


imprimir();

remover('b');

imprimir();
}

Obs: I put a "printf("Test")" after the loop(In the function inserts)which is where the program to.

I decided how to make the code after a few attempts and manipulations in pointer positions. However, the reason I made a mistake I don’t know. I just manipulated the whole code to try to make it work. I will now post the correct code.

 #include<stdio.h>
 #include<stdlib.h>

   struct TNoDeCaractere
   {
   char caractere;
   struct TNoDeCaractere *proximo;
    };

    struct TNoDeCaractere *inicio;

    void insere(char valor){
    struct TNoDeCaractere *p, *np;
   //Se a lista está vazia, cria um nó e faz "inicio"apontar para ele.
   if(inicio == NULL){
   np=malloc(sizeof(struct TNoDeCaractere));
  (*np).caractere= valor;
  (*np).proximo =np;
  inicio=np;

  }else{//Caso contrário, ou seja, se a lista não está vazia...
  p=inicio;
  //varre toda a lista,
  while((*p).proximo !=inicio){
  p=(*p).proximo;}
 //Cria novo nó e insere no final.
 np=malloc(sizeof(struct TNoDeCaractere));
 (*np).caractere=valor;
 (*np).proximo=inicio;
 // e liga a lista existente ao novo nó.
(*p).proximo=np;
}
}
void imprimir(){
 struct TNoDeCaractere *p;
 p=inicio;
  while((*p).proximo !=inicio){
    printf("Valor: %c \n",(*p).caractere);
     p=(*p).proximo;
 }
 printf("Valor: %c \n",(*p).caractere);// Linha para imprimir ultima letra.
 }
void remover(char valor)
 {
  struct TNoDeCaractere *pAnt, *p;
   //Verifica se a partir do segundo nó, há nó a ser retirado.
  pAnt=inicio;
  p=(*inicio).proximo;
  while(p!=inicio)
    {
        if((*p).caractere == valor)
        {

            (*pAnt).proximo=(*p).proximo;free(p);
            p=(*pAnt).proximo;
        }else{
            pAnt=(*pAnt).proximo;
            p=(*p).proximo;
            }
    }//Testa se a lista estácom o valor aser retirado no primeiro nó
    if((*inicio).caractere == valor)
    {

        p=(*inicio).proximo;
        free(inicio);
        inicio=p;
       }

}




int main(){

inicio=NULL;


insere('G');insere('a');insere('b');
insere('r');insere('i');insere('e');insere('l');


imprimir();

remover('b');

imprimir();
}

Answer 1

struct Tnodecaractere { character struct Tnodecharacter *next; };

struct Tnodecharacter *inicio = NULL;

void inserts(char value) { //good practice //always initialize the variables that will be used struct Tnodecharacter *p = NULL, *np = NULL; //If the list is empty, create a node and "start" point to it. if (start == NULL) { //good practice //when allocating memory always test to see if no error occurred if ((np = (struct Tnodecharacter *) malloc(sizeof(struct Tnodecharacter))) == NULL) { printf("Memory allocation failure n"); } Else { np->character = value; np->proximo = np; start = np; } } Else {//Otherwise, that is, if the list is not empty... p = start; //scan the entire list, while (p->proximo != start) { p = p->proximo; } //Create new node and insert at the end. //good practice //when allocating memory always test to see if no error occurred if ((np = (struct Tnodecharacter *) malloc(sizeof(struct Tnodecharacter))) == NULL) { printf("Memory allocation failure n"); } Else { np->character = value; np->proximo = start; // and connects the existing list to the new node. p->proximo = np; } } } void print() { struct Tnodecharacter *p = start; //p = start; while (p->proximo != start) { printf("Value: %c n", p->character); p = p->proximo; } printf("Value: %c n", p->character);// Line to print last letter. } void remove(char value) { struct Tnodecharacter *pant = start; struct Tnodecharacter * p = start->near; //Check if from the second node there is node to be removed. // while (p != start) { if (p->character == value) { pant->proximo = p->proximo; free(p); p = pant->proximo; } Else { pant = pant->proximo; p = p->proximo; } }//Test if the list has the Aser value removed at the first node if (start->character == value) { p = start->near; free(start); start = p; } } //no need to use pointers when you use pointers directly //This may confuse the compiler by indexing a memory address //This may be the problem that your program is going into a screw. int main() { struct Tnodecharacter * top = NULL; struct Tnodecharacter * next = NULL; inserts('G'); inserts('a'); inserts('b'); inserts('r'); inserts('i'); inserts('e'); inserts('l'); print(); remove ('b'); print(); // //always release all memory used //because if you do not do this and run the program several times there may be a lack of memory in the system //or other problems, because the system thinks that this memory is still in use top = start; next = start->next; while (next != start) { top->proximo = next->proximo; free(next); next = top->proximo; } free(start); }