Question

Ok so I’m sure there’s a simple fix that I’m missing, but right now my code is causing a segment fault on the line “A[i]->key = 0;.” The Record* Item part is a necessity for the program, so I need to make it work this way for an assignment I’m working on, however if I do change it so that Item becomes a non-pointer typedef of Record, then I can use A[i].key no problem. I just need a nudge in the right direction so that I can make standInput correctly assign values to an array of pointers to records. Thanks!

Item.h:

#include "stdio.h"
#include "stdlib.h"

typedef int keyType;

struct Record
{
    keyType key;
    int other;
};
typedef struct Record* Item;

void standInput(Item *A, int n)
{
    int i, input;
    for(i = 0; i <= n-1; i++)
    {
        A[i]->key = 0;
        printf("%d ", A[i]->key);
    }
}

Main:

#include "stdio.h"
#include "stdlib.h"
#include "Item.h"

int main()
{
    int n;
    Item *A;
    printf("Enter a length for the array: ");
    scanf("%d", &n);
    A = (Item*)malloc(n * sizeof(Item));
    standInput(A, n);
    return 0;
}

Answer 1

The values in A are all uninitialized, but you’re using them as struct Record pointers anyway. If you want to have A continue holding pointers (rather than the structs directly), then you need to allocate space for A and for each item pointed to by A.