CODEWITHSUNDEEP
cvectorstructdynamic-allocation
PlayHardGoPro
PlayHardGoPro

Reputation: 2933

Allocate memory dynamically of a vector of struct

I can't access my pointer by index notation in main function. The way I'm passing the pointer as paramter to the functions, is that right ? I tried without the & and It didnt work neither. Here is my code: 

//My Struct
typedef struct{
    int a;
    double d;
    char nome[20];
}contas;

//Function to allocate memory
void alloca_vetor(contas *acc, int linhas){
    acc = malloc(linhas * sizeof(contas));

    if(acc == NULL){
       printf("ERRO AO ALOCAR MEMORIA\n"); 
       exit(0);
    }

    printf("ALLOCATION SUCCESSFUL");
}

//Function to fill the vector
void fill_vetor(contas *acc, int linhas){
    int i,a;

    for(i=0; i< linhas; i++){
        acc[i].a = i;
    }
    printf("FILL SUCCESSFUL !\n");

    for(i=0; i< linhas; i++){
        printf("%i\n", acc[i].a);
    }
}

int main()
{
    int i,  num_linhas = 5;
    contas *array;

    alloca_vetor(&array, num_linhas);
    fill_vetor(&array, num_linhas);

// ERROR HAPPENS HERE - Segmentation Fault
    for(i=0; i < num_linhas; i++){
        printf("%i\n", array[0].a);
    }

    free(array);
    return 0;
}

Upvotes: 2

Views: 845

Answers (1)

Vlad from Moscow
Vlad from Moscow

Reputation: 310990

Rewrite function alloca_vetor the following way

void alloca_vetor( contas **acc, int linhas ){
    *acc = malloc(linhas * sizeof(contas));

    if(*acc == NULL){
       printf("ERRO AO ALOCAR MEMORIA\n"); 
       exit(0);
    }

    printf("ALLOCATION SUCCESSFUL");
}

And call function fill_vetor like

fill_vetor(array, num_linhas);

Upvotes: 3

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