What does the scope of validity of a variable describe?

What is the Worst Case time complexity of a standard Bubble Sort algorithm?

Which loop is best for a fixed number of

iterations?

Which mode is used to open the file for both reading and writting?

Which of the following is TRUE about blocks?

What is the output?

struct node *a = malloc(sizeof(struct node));

struct node *b = malloc(sizeof(struct node));

a->data = 1;

b->data = 2;

a->next = b;

b->next = a;

printf("%d %d", a->next->data, b->next->data);

Why use functions?

int a[] = {10, 20, 30};

int *p = a;

printf("%d", *(p + 1));