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simpler exercise for now

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mustakimur khandaker 2022-02-08 10:39:59 -05:00
parent 2d02da3e2e
commit c1655da38f
5 changed files with 46 additions and 366 deletions
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281
exercises/doubly_linked_list/README.md
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@ -1,281 +0,0 @@
Implement a doubly linked list similar to the following:
```c
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
struct node {
int data;
int key;
struct node *next;
struct node *prev;
};
//this link always point to first Link
struct node *head = NULL;
//this link always point to last Link
struct node *last = NULL;
struct node *current = NULL;
//is list empty
bool isEmpty() {
return head == NULL;
}
int length() {
int length = 0;
struct node *current;
for(current = head; current != NULL; current = current->next){
length++;
}
return length;
}
//display the list in from first to last
void displayForward() {
//start from the beginning
struct node *ptr = head;
//navigate till the end of the list
printf("\n[ ");
while(ptr != NULL) {
printf("(%d,%d) ",ptr->key,ptr->data);
ptr = ptr->next;
}
printf(" ]");
}
//display the list from last to first
void displayBackward() {
//start from the last
struct node *ptr = last;
//navigate till the start of the list
printf("\n[ ");
while(ptr != NULL) {
//print data
printf("(%d,%d) ",ptr->key,ptr->data);
//move to next item
ptr = ptr ->prev;
}
}
//insert link at the first location
void insertFirst(int key, int data) {
//create a link
struct node *link = (struct node*) malloc(sizeof(struct node));
link->key = key;
link->data = data;
if(isEmpty()) {
//make it the last link
last = link;
} else {
//update first prev link
head->prev = link;
}
//point it to old first link
link->next = head;
//point first to new first link
head = link;
}
//insert link at the last location
void insertLast(int key, int data) {
//create a link
struct node *link = (struct node*) malloc(sizeof(struct node));
link->key = key;
link->data = data;
if(isEmpty()) {
//make it the last link
last = link;
} else {
//make link a new last link
last->next = link;
//mark old last node as prev of new link
link->prev = last;
}
//point last to new last node
last = link;
}
//delete first item
struct node* deleteFirst() {
//save reference to first link
struct node *tempLink = head;
//if only one link
if(head->next == NULL){
last = NULL;
} else {
head->next->prev = NULL;
}
head = head->next;
//return the deleted link
return tempLink;
}
//delete link at the last location
struct node* deleteLast() {
//save reference to last link
struct node *tempLink = last;
//if only one link
if(head->next == NULL) {
head = NULL;
} else {
last->prev->next = NULL;
}
last = last->prev;
//return the deleted link
return tempLink;
}
//delete a link with given key
struct node* delete(int key) {
//start from the first link
struct node* current = head;
struct node* previous = NULL;
//if list is empty
if(head == NULL) {
return NULL;
}
//navigate through list
while(current->key != key) {
//if it is last node
if(current->next == NULL) {
return NULL;
} else {
//store reference to current link
previous = current;
//move to next link
current = current->next;
}
}
//found a match, update the link
if(current == head) {
//change first to point to next link
head = head->next;
} else {
//bypass the current link
current->prev->next = current->next;
}
if(current == last) {
//change last to point to prev link
last = current->prev;
} else {
current->next->prev = current->prev;
}
return current;
}
bool insertAfter(int key, int newKey, int data) {
//start from the first link
struct node *current = head;
//if list is empty
if(head == NULL) {
return false;
}
//navigate through list
while(current->key != key) {
//if it is last node
if(current->next == NULL) {
return false;
} else {
//move to next link
current = current->next;
}
}
//create a link
struct node *newLink = (struct node*) malloc(sizeof(struct node));
newLink->key = newKey;
newLink->data = data;
if(current == last) {
newLink->next = NULL;
last = newLink;
} else {
newLink->next = current->next;
current->next->prev = newLink;
}
newLink->prev = current;
current->next = newLink;
return true;
}
void main() {
insertFirst(1,10);
insertFirst(2,20);
insertFirst(3,30);
insertFirst(4,1);
insertFirst(5,40);
insertFirst(6,56);
printf("\nList (First to Last): ");
displayForward();
printf("\n");
printf("\nList (Last to first): ");
displayBackward();
printf("\nList , after deleting first record: ");
deleteFirst();
displayForward();
printf("\nList , after deleting last record: ");
deleteLast();
displayForward();
printf("\nList , insert after key(4) : ");
insertAfter(4,7, 13);
displayForward();
printf("\nList , after delete key(4) : ");
delete(4);
displayForward();
}
```
Instead of maintaining head, last, and current in the global; maintain them inside main() and send them as reference to the functions, as required. Feel free to change function arguments as required.

83
exercises/doubly_linked_list/dlist.rs
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/* define your structure here
*/
fn isEmpty(???) -> bool {
}
fn length(???, ???) -> i32 {
}
fn displayForward(???) {
}
fn displayBackward(???) {
}
fn insertFirst(???, key: i32, data: i32) {
}
fn insertLast(???, key: i32, data: i32) {
}
fn deleteFirst(???, ???) -> ???{
}
fn deleteLast(???, ???) -> ??? {
}
fn delete(???, ???, ???, key: i32) -> ??? {
}
fn insertAfter(???, ???, ???, key: i32, newKey: i32, data: i32) -> bool{
}
void main() {
/* declare your nodes here for head, last, and current
*/
insertFirst(???, 1, 10);
insertFirst(???, 2, 20);
insertFirst(???, 3, 30);
insertFirst(???, 4, 1);
insertFirst(???, 5, 40);
insertFirst(???, 6, 56);
println!("\nList (First to Last): ");
displayForward(???);
println!("\n");
println!("\nList (Last to first): ");
displayBackward(???);
println!("\nList , after deleting first record: ");
deleteFirst(???, ???);
displayForward(???);
println!("\nList , after deleting last record: ");
deleteLast(???, ???);
displayForward(???);
println!("\nList , insert after key(4) : ");
insertAfter(???, ???, ???, 4, 7, 13);
displayForward(???);
println!("\nList , after delete key(4) : ");
delete(???, ???, ???, 4);
displayForward(???);
}

6
exercises/students/README.md Normal file
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In this assignment, you will practice writing code relating to struct and ownership. Follow the code comments.
- Ensure you are not missing any shorthands possible we have discussed.
- Define methods means you call that using a `instance.fn()` approach.
- You can have regular functions to iterate over the vector and sorting (ascending or descending) reason.
- Make sure you follow best practices.
- Minimize number of warnings, if possible to zero.

38
exercises/students/students.rs Normal file
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struct Student {
name: String,
id: i32,
major: String,
gradyear: i32,
}
// define associate functions to create the following instances, use shorthand wherever available
// define methods to satisfy the requirements
// define functions to satisfy the requirements
fn main() {
// a vector<Student> and push the following instances
// an instance of student (Adam Helex, 1022, CS, 2022)
// an instance of student (Rob Delon, 1033, Bio, 2023)
// an instance of student (Jenny Susan, 1044, CS, 2023)
// an instance of student (Nick Frank, 1055, CS, 2022)
// an instance of student (Michael Dodge, 1066, Bio, 2023)
// Note: shorthand possible for Rob and Michael; Adam and Helex
// call a function that will return list of students graduating by year
// call a function that will return list of the last name of students
// call a function that will sort the students by their first name
// call a method that will return true if any two students are graduating same year
// call a method that will modify the student last name to a desired one
}

4
info.toml
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@ -1056,7 +1056,7 @@ mode = "compile"
hint = "" hint = ""
[[exercises]] [[exercises]]
name = "doubly-linked-list" name = "students"
path = "exercises/doubly_linked_list/dlist.rs" path = "exercises/students/students.rs"
mode = "compile" mode = "compile"
hint = "" hint = ""