[Solved] Resizing matrix in c

Dev Zone Code
1

I have a function that makes a matrix bigger in C. it works the first time you use it, but on the second time, I get "realloc(): invalid old size". Any ideas on what might be happening?

Here's the code:

int** resize_matrix(int** matrix, long org_size, long size_inc){

long new_size = org_size + size_inc;
int** new;
int* temp;

new = realloc(matrix, new_size*sizeof(int*));

for(long i=0; i<org_size; i++){
  //error happens here, when i=0, but only the second time you run it
  temp = realloc(new[i], new_size*sizeof(int));
  new[i] = temp;
  //clears the added space
  for(long i2=org_size; i2<new_size; i2++){
    new[i][i2] = 0;
  }
}

for(long i = org_size; i<new_size; i++){
  new[i] = calloc(new_size, sizeof(int));
}

return new;
}

I call the function with:

adjacency_matrx = resize_matrix(adjacency_matrix, number_of_nodes, 100);

2

The problem was a realloc made after the call to resize_matrix, that just so happened to stop my output at the right time to make me think it was resize_matrix that caused it. Is there a way to delete the thread?

1 Like
3

No, threads can't be deleted. But I marked it solved for you.