Thread: Read inputs for an dynmaically allocated array

I want to read user's input for my array using pointers, allocated space, read elements and return pointer.

my function is called read:

Code:

double read *read_vector (int n) // n is the size of array, which user will enter

int *vec = (int *) malloc (sizeof(int)*n);
int i;
for (i=0; i<10; i++)
            vec[i] = n;
return vec;

}

but this code is not working, giving me segmentation fault, any help please?

this is part of the main function i am using to read it:

Code:

int n;
  double *vector;
  /* Vector */
  printf("Vector\n");
  printf("Enter number of entries: ");
  scanf("%d",&n);
  printf("Enter %d reals: ",n);
  vector = read(n);

Your *vec variable should be a double pointer since that is what you are returning and your for loop should probably iterate from i to n, not 10. At the moment your function isn't actually reading anything it just initializes the array with n, but I guess you know that.

how do I read the inputs in?

changed some things:

Code:

double *read_vector(int n){
double *vec = (double *) malloc (sizeof(double)*n);
int i;
for (i=0; i<n; i++)
       vec[i] = n;
       return vec;
}

now how do i store the users inputs?

this is my print vector function:

Code:

/* Print a vector with n entries pointed to by vec. */
void print_vector(int n, double *vec){
int i;
for (i=0; i<n; i++) {
     printf("%d", vec[i]);
}

is this correct?

my read_vector is not even letting me enter the numbers for some reason.

Originally Posted by Lina_inverse

my read_vector is not even letting me enter the numbers for some reason.

Because you don't read any numbers. You just assign "n" to each member of "vec".

For reading user input you probably want to use scanf().

Bye, Andreas