Classwork 22

Logistics

Due: Wednesday, April 26th AoE.
Submission instructions: make sure that the required file (find_and_delete.c) is in your /classwork/week14/wed/ directory.
Note: this assignment is ungraded.

Learning outcomes

Practice writing a linked list function

Assignment

If on campus and connected to a MSU network:

Log in to the server.
From your home directory, navigate to classwork/week14/wed/, creating directories week14 and wed if necessary.
Copy the find_and_delete.c file from /public/classwork/week14/wed and fill in delete_digit so that it finds the node with the given integer value and deletes it from the list. You are not required to free the memory. (You will get practice with this on Lab 7.) However, do be sure that you deal with the case when the node to delete is the first one!

If off campus:

Copy the code below. Using a C compiler of your choice (if you don’t have one, use https://www.jdoodle.com/c-online-compiler/), fill in the create_new_digit function as described above so that the program prints
```
List is:
1->4->9->16->25->36->49->64->81->
List is:
4->9->16->25->36->49->81->
```
In a DM to Lucy on Discord, copy your code. Surround your code with three backticks (` ` `, found under the tilde (~) on your keyboard) on the first line and last line so that Discord doesn’t think asterisks are meant to italicize. Or attach it as a file.

Autograder

You can run the autograder yourself by running

/public/classwork/week14/wed/autograder.sh

The autograder.txt file will be created or replaced. You may get a few lines of output about not being able to remove files, etc. This is okay.

For those who DM their code, if your program has the output

List is:
1->4->9->16->25->36->49->64->81->
List is:
4->9->16->25->36->49->81->

you will get full credit.

Code to copy

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

typedef struct digit {
    int d;
    struct digit* next;
} digit;

void print_list(digit* head) {
    digit* temp = head;

    while (temp != NULL) {
        printf("%d->", temp->d);
        temp = temp->next;
    }
    printf("\n");
}

digit* create_new_digit(int d) {
    digit* new = malloc(sizeof(digit));
    new->d = d;
    new->next = NULL;
    return new;
}

void insert_digit_at_end(digit** head, digit* new) {
    // find end
    digit* current = *head;
    if (*head == NULL) {
        *head = new;
    } else {
        while (current->next != NULL) {
            current = current->next;
        }
        // found end
        current->next = new;
    }
}

void delete_last_digit(digit** head) {
    digit* current = *head;
    digit* to_free;
    if (current == NULL) {
        // no nodes
        return;
    } else if (current->next == NULL) {
        //
        *head = NULL;
        free(current);
    } else {
        while (current->next->next != NULL) {
            current = current->next;
        }
        to_free = current->next;
        current->next = NULL;
        free(to_free);
    }
}

void delete_digit(digit** head, int d) {
    // TODO
}


int main(void) {
    digit* head;

    for (int i = 1; i < 10; i++) {
        insert_digit_at_end(&head, create_new_digit(i*i));
    }
    printf("List is:\n");
    print_list(head);
    delete_digit(&head, 64);
    delete_digit(&head, 1);
    printf("List is:\n");
    print_list(head);

}