Pointer/struct (C) - IDE: Eclipse

Question

I've a problem with my code. I have to input data into a struct for n times. To choose the cardinality of the struct during the declaration of the variables, I write: struct table T[DIM]; but.. DIM is a constant...so ... I would like to make somehow, dynamic the constant. I would do this, using a pointer. Then...:

const int DIM
int *p=&DIM

Next, I'm going to load the struct with data using a for. But before starting the for I want to ask what is the cardinality of the struct in this way:

printf("\nEnter the number of flights to manage");
scanf("%d", &*p)

Everything seems to work but while I run the insertion cycle, in the second or third cycle, this crash. Now I will enter the relevant code part:

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

struct table {
    int cod;
    char departure[20];
    char arrival[20];
    int tot_seats;
    int seats_busy;
};

int main(int argc, char *argv[]){
const int DIM;
int *p=&DIM
struct table T[DIM];
int menu=0;
int menu1=0;
int I=0;
int TAB=0;
int flight;
int cont=0;

printf("---------------------------Airports------------------------\n\n");

while(menu!=3){
    printf("\nWelcome to the software! Choose the most suitable function for your needs: \n \n");
    printf("Do you run an airport or travel agency? Answer by typing the number associated with the response\n");
    printf("1) Airports\n");                                                  /*Apro il primo menù*/
    printf("2) Travel agency\n");
    printf("3) Exit\n");
    scanf("%d", &menu);
    printf("\n--------------------------------------------------------------------- \n \n");

    switch(menu){
    case 1: system("cls");
            printf("\nYou have chosen the airport option\n-- You can now load the table --\n \n");


printf("\nEnter the number of flights to manage\n");
            TAB=1;
            for(I=0;I<DIM;I++){
                printf("\n You are completing the line %d \n", I+1);
                getchar();

                printf("\nEnter the departure city:");
                gets(&T[I].departure);

                printf("\nEnter the city of arrival:");
                gets(&T[I].arrival);

                printf("\nEnter the flight code:");
                scanf("%d", &T[I].cod);

                printf("\nEnter the total number of flight seats:");
                scanf("%d", &T[I].tot_seats);
            }
            printf("CODE -- DEPARTURE -- ARRIVAL-- TOT_SEATS\n");
            for(I=0;I<DIM;I++){
                printf("%d -- %s -- %s -- %d \n", T[I].cod, T[I].partenza,T[I].arrivo,T[I].tot_posti);
            }
            break;

Also eclipse tells me that in correspondence with:

gets(&T[I].departure);

and

gets(&T[I].arrival);

there is an error: passing argument 1 of 'gets' from incompatible pointer type [enabled by default].

How can I fix both errors? Thanks in advance!

Answer 1

This is why malloc has been created :) You can allocate dynamically an array with the size, given as an input, like the number of flights in your example. if you have p flights you can create a table

T = (int) malloc(p*sizeof(int);

then you can iterate through your table from 0 to p. regards