Week 10 Weekly Test Questions

Download array_max.c here, or copy it to your CSE account using the following command:

cp -n /web/cs1511/20T1/activities/array_max/array_max.c .

Your task is to add code to this function in array_max.c:

// Return the largest value in a given array.
int array_max(int size, int array[size]) {
    // Put your code here
    return 42;
}

The file array_max.c contains a main function which reads values into an array and calls array_max.

Here is how array_max.c should behave after you add the correct code to the function array_max:

dcc array_max.c -o array_max
./array_max
Enter array size: 5
Enter array values: 1 2 3 4 5
Maximum value is 5.
./array_max
Enter array size: 6
Enter array values: -1 -3 -9 -17 -2 -8
Maximum value is -1.

When you think your program is working you can autotest to run some simple automated tests:

1511 autotest array_max

give cs1511 test10_array_max array_max.c

Download list_get_middle.c here, or copy it to your CSE account using the following command:

cp -n /web/cs1511/20T1/activities/list_get_middle/list_get_middle.c .

Your task is to add code to this function in list_get_middle.c:

// Return middle element of a linked list
// if list contains [6,7,8,9,10]  8 is returned
// if a list has even number of elements, first of middle two elements returned
// if list contains [1,2,3,4] 2 is returned
// list can not be empty
int get_middle(struct node *head) {

    // PUT YOUR CODE HERE (change the next line!)
    return 42;

}

Add code to get_middle so that its returns the middle value of the list. If the list an even number of elements the first of the 2 elements in the middle of the list should be returned.

For example if the linked list contains these 8 elements:

1, 7, 8, 9, 13, 19, 21, 42

get_middle should return 9 because 9 and 13 are the middle two elements/

And or example if the linked list contains these 8 elements:

1, 2, 8, 1,  42

get_middle should return 8 because it is the middle element.

get_middle can assume the list is not empty.

Testing

This main function:

• converts the command-line arguments to a linked list
• assigns a pointer to the first node in the linked list to head
• calls list_get_middle(head)
• prints the result.

Do not change this main function. If you want to change it, you have misread the question.

Your list_get_middle function will be called directly in marking. The main function is only to let you test your list_get_middle function

Here is how you use main function allows you to test list_get_middle:

dcc list_get_middle.c -o list_get_middle
./list_get_middle 1 2 4 8 16 32 64 128 256
16
./list_get_middle 2 4 6 5 8 9
6
./list_get_middle 13 15 17 19 18
17
./list_get_middle 42 4
42
./list_get_middle 42
42

Assumptions/Restrictions/Clarifications.

get_middle can assume the list has at least one element.

get_middle should not change the linked list it is given. Your function should not change the next or data fields of list nodes.

get_middle should not use arrays.

get_middle should not call malloc.

get_middle should not call scanf (or getchar or fgets).

get_middle should not print anything. It should not call printf.

Do not change the supplied main function. It will not be tested or marked.

When you think your program is working you can autotest to run some simple automated tests:

1511 autotest list_get_middle

give cs1511 test10_list_get_middle list_get_middle.c

Download list_delete_highest.c here, or copy it to your CSE account using the following command:

cp -n /web/cs1511/20T1/activities/list_delete_highest/list_delete_highest.c .

Your task is to add code to this function in list_delete_highest.c:

//
// Delete the node(s) in the list that contain the highest value
// The deleted node(s) are freed.
// The head of the list is returned.
//
struct node *delete_highest(struct node *head) {

    // PUT YOUR CODE HERE (change the next line!)
    return NULL;

}

struct node {
    struct node *next;
    int          data;
};

Add code to delete_highest so that it deletes the all nodes in the linked list whose data field are equal to the highest data value in the list.

delete_highest should return a pointer to the new list.

If the list is now empty delete_highest should return NULL.

delete_highest should call free to free the memory of any node it deletes.

For example if the linked list contains these 8 elements:

16, 7, 8, 19, 13, 19, 2, 12

delete_highest should return a pointer to a list with these elements:

16, 7, 8, 13, 2, 12

Testing

This main function:

• converts the command-line arguments to a linked list
• assigns a pointer to the first node in the linked list to head
• calls delete_highest(head)
• prints the result.

Do not change this main function. If you want to change it, you have misread the question.

Your delete_highest function will be called directly in marking. The main function is only to let you test your delete_highest function

cp -n /web/cs1511/20T1/activities/list_delete_highest/list_delete_highest.c .
dcc list_delete_highest.c -o list_delete_highest
./list_delete_highest 16 7 8 19 13 19 2 12
[16, 7, 8, 13, 2, 12]
./list_delete_highest 200 150 27 200 200
[150, 27]
./list_delete_highest 4 6 2 4 6
[4, 2, 4]
./list_delete_highest 42
[]
./list_delete_highest
[]

Assumptions/Restrictions/Clarifications.

delete_first should not change the data fields of list nodes.

delete_highest should not use arrays.

delete_highest should not call malloc.

delete_highest should not call scanf (or getchar or fgets).

delete_highest should not print anything. It should not call printf.

Do not change the supplied main function. It will not be tested or marked.

When you think your program is working you can autotest to run some simple automated tests:

1511 autotest list_delete_highest

give cs1511 test10_list_delete_highest list_delete_highest.c