如何在结构中直接将指针分配给新结构？

Question

can you help me please?

I want to manipulate a doubly linked liste that manage a bank accounts, but I don't know why it doesn't work even if I tried vainly to correct all my mistakes. Certainly, It's the first time that i use this nested structer and i don't know how to access from the main structre to the other ones (idt,idf).

2 Questions:

-is this method accepted "pnt->idt.dn.j_n" (pnt is a pointer on CompteBancaire)?

-when i traverse the main linked liste using a pointer and i want add a particular struct to my new liste (YoungCustomers), is there any possibility to assign the struct pointer to a new struct that i'll put it in my new liste, instead of assigning each element to it? Thanks in advance.

#include <stdio.h>
#include <stdlib.h>
#include <string.h >
typedef struct
{  int j_n,m_n,a_n;
}dateDeNaissance;

typedef struct
{  char nom[15];
   char prenom[15];
    dateDeNaissance dn;
}identite;

typedef struct
{  int numCompte;
   char nomBanque[20];
}identifiant;
/* ------------THE MAIN STRUCT-------------*/
typedef struct
{  identite idt;
   identifiant idf;
   float solde;
   struct CompteBancaire *next;
   struct CompteBancaire *prc;
}CompteBancaire;
/* -----------STRUCT OF YOUNG CUSTOMERS----------------*/
typedef struct
{ CompteBancaire *Cpt;
 struct ClientJeune *next;
}ClientJeune;
/*-------------GLOBAL POINTERS------------- */
CompteBancaire *first=NULL;
CompteBancaire *first2=NULL;
/*---------- CREATE A BANC ACOUNTE ---------*/
void saisiNovCompt (char nom[],char prn[],int j,int m,int a,int numCpt,char nomB[],float Solde) //21:32
{  CompteBancaire *nov=malloc(sizeof(CompteBancaire)),pnt=first;
   strcpy (nov->idt.nom,nom);
   strcpy (nov->idt.prenom,prn);
   nov->idt.dn.j_n=j;
   nov->idt.dn.m_n=m;
   nov->idt.dn.a_n=a;
   nov->idf.numCompte=numCpt;
   nov->prc=NULL;
   strcpy (nov->idf.nomBanque,nomB);
   nov->solde=Solde;
   if (first==NULL)
   {  nov->next=NULL;
      nov->prc=NULL;
      first=nov;
   }
   else
   {  first=nov;
      nov->next=pnt;
      pnt->prc=nov;
   }
}
/* --------SAVE AN ACCOUNTE IN FILE-------------*/
void fichier (CompteBancaire *pnt)
{  FILE *Compte;
   Compte=fopen("comptBancaire.txt","w");
   fprintf("nom: %s\nprenom: %s\ndate de naissance: %d/%d/%d\nnum de compte: %d\nnom de la banque: %s\nsolde: %.2f\n",
           pnt->idt.nom,pnt->idt.prenom,pnt->idt.dn.j_n,pnt->idt.dn.m_n,pnt->idt.dn.a_n,pnt->idf.nomCompte,pnt->idf.nomBanque);
  fclose(Compte);
}
/* -------------- SAVE AN ACCOUNT THAT IT'S NUMBER IS GIVEN BY THE USER ------------------*/
void afficheParNum (int numCpt)
{  CompteBancaire *pnt=first;
   if (first==NULL)
      printf ("la liste est vide \n");
   else
   {  while (pnt!=NULL && pnt->idf.numDeCompt!=numCpt)
             pnt=pnt->next;
      if (pnt==NULL)
         printf("Compte non trouve !\n");
      else
         fichier(pnt);
   }
}
/*-----------------REMOVE AN ACCOUNT THAT IT'S NUMBER IS GIVEN BY THE USER--------------------*/
void suppCompt (int numCpt)
{  CompteBancaire *pnt=first;
   if (first==NULL)
       printf("la liste vide !\n");
   else
   {   while (pnt!=NULL && pnt->idf.numCompte!=numCpt)
              pnt=pnt->next;
       if (pnt==first) // remove in beginning
       {  first=pnt->next;
          free(pnt);
       }
       else if (pnt->next==NULL) // remove at the end
       {  (pnt->prc)->next=NULL;
           free(pnt);
       }
       else  // remove in the middle
       {  (pnt->prc)->next=pnt->next;
          (pnt->next)->prc=pnt->prc;
           free(pnt);
       }
       }
   }
   }
/* ------------------REMOVE THE ACCOUNT IF THE BALANCE IS LESS THEN 0 DH--------------------------*/
void suppInf00 ()
{CompteBancaire *pnt2=first,*pnt=NULL;
   if (first==NULL)
       printf("la liste vide !\n");
   else
   {   while (pnt2!=NULL) {
       pnt=pnt2;
       if (pnt->solde <0) {
       if (pnt==first) // remove in the beginning
       {  first=pnt->next;
          free(pnt);
       else if (pnt->next==NULL) // remove at the end
       {  (pnt->prc)->next=NULL;
           free(pnt);
       }
       else  // remove in the middle
       {  (pnt->prc)->next=pnt->next;
          (pnt->next)->prc=pnt->prc;
           free(pnt);
       }
       }
        pnt2=pnt2->next;
   }
   }
   }

}
/* -----------CREAT A LISTE OF YOUNG PEAPLE--------------------- */
void under35 ()
{  ClientJeune nov,*pnt=first;
   if (first==NUll)
      printf("liste vide !\n");
   else
   {  while (pnt!=NULL)
      if (2015-(pnt->idt.dn.a_n)<=35)
      {   nov->Cpt=pnt;
          if (first2==NULL)
             nov->next=NULL;
           else
           {  nov->next=first2;
              first2=nov;
           }
      }
   }
}
/* -----------------DISPLAY ALL ACCOUNTS---------------------*/
void afficage ()
{CompteBancaire *pnt=first;
 if(first==NULL)
    printf("liste vide !\n");
 else
 { while (pnt!=NULL)
   printf("nom: %s\nprenom: %s\ndate de naissance: %d/%d/%d\n num de compte: %d\nnom de la banque: %s\nsolde: %.2f\n\n",
           pnt->idt.nom,pnt->idt.prenom,pnt->idt.dn.j_n,pnt->idt.dn.m_n,pnt->idt.dn.a_n,pnt->idf.nomCompte,pnt->idf.nomBanque);
     pnt=pnt->next;
 }

}
int main()
{int n=0,c,j,m,a,numC;
 float S=0;
char A[15],B[15],C[15];
printf("-----------------Menu-------------------\n");
printf("1----------------------------------Saisi\n");
printf("2----------------------------------affichage par num de compte \n");
printf("3----------------------------------Suppression d'un compte \n");
printf("4----------------------------------Supp inf 00 DH\n");
printf("5----------------------------------under 35ans\n");
printf("6----------------------------------Affichage\n\n");
while (n==1)
{
    printf("donner votre choix :");
    scanf("%c",&c);
    switch (c)
    { case 1:printf("donner le nom:");scanf("%s",A);
             printf("donner le prenom:");scanf("%s",B);
             printf("donner la date de naissance jj mm aa:");scanf("%d %d %d",&j,&m,&a);
             printf("donner le num du compte:");scanf("%d",&numC);
             printf("donner le nom de la banque:");scanf("%s",C);
             printf("donner le solde :");scanf("%f",&S);
             saisiNovCompt(A,B,j,m,a,numC,C,S);break;
     case 2:printf("donner le num du compte:");scanf("%d",&numC);
            afficheParNum(numC);break;
     case 3:printf("donner le num du compte:");scanf("%d",&numC);
            suppCompt(numC);break;
     case 4:suppInf00();
            printf("suppression solde inf 0 à ete efectue\n");break;
     case 5:under35 ();
            printf("une nouvelle liste a ete creer\n");break;
     case 6:affichage();
     default:printf("tapper 1/2/3/4/5/6 !!\n");
    }
    printf("tapper 1:");
    scanf("%d",&n);
}
    return 0;
}

Answer 1

I don't know if I understood correctly, but if you want to initialize a struct AND assigning it's adress to a pointer

Suppose you have

struct XXX
{
    T1 arg1;
    T2 arg2;
    T3 arg3;
    .
    .
    .
};

you may want to do something like :

struct XXX *ptr = &(struct XXX){arg1, arg2, arg3, ...};

maybe this is not the most elegant way, but it works.