feat: integrate hash table with student management functions by ayoubkad · Pull Request #2 · ayoubkad/Mini-Database

ayoubkad · 2026-01-28T15:43:52Z

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Pull request overview

This PR integrates a hash table data structure with the existing student management system to improve search performance. The hash table provides O(1) average-case lookup time for students by CNE (student ID), replacing the previous O(n) linear search through the linked list.

Changes:

Integrated hash table alongside the existing linked list structure for efficient student lookups
Updated all student management functions (add, delete, search, delete_all) to maintain both data structures
Fixed critical bugs including assignment operator misuse and struct syntax errors
Improved header file dependencies by using forward declarations to reduce circular includes

Reviewed changes

Copilot reviewed 9 out of 11 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
undo_stack.h	Added hash_table parameter to undo functions; moved student_data definition here; added forward declarations
undo_stack.c	Updated execute_undo to accept hash_table and propagate it to add/delete operations
student.h	Removed duplicate student_data definition; updated function signatures to include hash_table; removed merge sort functions
student.c	Updated add_student, delete_student, search_student_by_cne, and delete_all_students to work with hash table; fixed NULL check bug; added populate_hash_table function
hash_table.h	Fixed struct syntax error; replaced include with forward declaration; renamed search to search_hash
hash_table.c	Added student.h include; made index const; removed print statement from search function
main.c	Created and initialized hash table; updated all function calls with hash_table parameter; moved variable declaration to top
arbres_binaire.h	Replaced undo_stack.h include with forward declaration
arbres_binaire.c	Added student.h include; removed BOM character
my_data.db	Binary database file added to repository
mini_db	Binary executable added to repository

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Copilot · 2026-01-28T15:51:27Z

undo_stack.h

+// Supprime un étudiant de la liste en utilisant son CNE.



Moving the comment to a separate line improves code readability, but consider keeping the comment on the same line as the function declaration or removing it entirely since it duplicates information from the function name.

Suggested change

// Supprime un étudiant de la liste en utilisant son CNE.

Copilot · 2026-01-28T15:51:27Z

student.c

+#include "student.h"
+#include "hash_table.h"
 #include "arbres_binaire.h"
 #include "undo_stack.h"


The student_data type is now defined in undo_stack.h and used in both save_database and load_database functions. This creates a potentially confusing dependency where student.c must include undo_stack.h just to get the student_data structure definition, even though these database functions are not related to undo functionality. Consider moving student_data to student.h or creating a separate types header to maintain better separation of concerns.

Copilot · 2026-01-28T15:51:27Z

student.c

+        // Réinitialiser le pointeur next (sera défini correctement manuellement)
        new_student->next = NULL;

-        // Ajouter l'étudiant à la fin de la liste chaînée
-        // Cela reconstruit la structure de liste originale
-        add_student(list, new_student, NULL);
+        if (list->tete == NULL) {
+            list->tete = new_student;
+            list->queues = new_student;
+        } else {
+            list->queues->next = new_student;
+            list->queues = new_student;
+        }


The load_database function has been changed to manually add students to the list instead of calling add_student. This avoids calling add_student which would now try to insert into the hash table (which hasn't been populated yet during loading). However, the hash table is populated separately after load_database returns via populate_hash_table on line 26 of main.c. This approach is correct but the comment should be updated to reflect that the hash table population happens separately after loading.

Copilot · 2026-01-28T15:51:28Z

student.c

+ * @param stack Structure de donnee pour stocker historique de suppression
 */
-void delete_student(list_student *list, char *cne_to_delete, UndoStack *stack) {
+void delete_student(hash_table* ht ,list_student *list, char *cne_to_delete, UndoStack *stack) {


Missing space after the comma in the parameter list. Should be "hash_table* ht, list_student *list" or preferably "hash_table *ht, list_student *list" for consistency with C style conventions where the asterisk is placed next to the variable name rather than the type.

Suggested change

void delete_student(hash_table* ht ,list_student *list, char *cne_to_delete, UndoStack *stack) {

void delete_student(hash_table *ht, list_student *list, char *cne_to_delete, UndoStack *stack) {

Copilot · 2026-01-28T15:51:28Z

main.c

                fgets(cne_buffer, 15, stdin);
                cne_buffer[strcspn(cne_buffer, "\n")] = 0;
-                delete_student(my_db, cne_buffer, my_stack);
+                delete_student(table_hachage,my_db, cne_buffer, my_stack);


Missing space after the comma in the function call. Should be "delete_student(table_hachage, my_db, cne_buffer, my_stack);" for consistency with formatting conventions.

Suggested change

delete_student(table_hachage,my_db, cne_buffer, my_stack);

delete_student(table_hachage, my_db, cne_buffer, my_stack);

Copilot · 2026-01-28T15:51:29Z

undo_stack.h

+typedef struct {
+    char nom[20];
+    char prenom[20];
+    Date date_naissance;
+    char CNE[15];
+    char filiere[30];
+    float moyenne;
+} student_data;


The Date type is used in student_data but is not defined in this header file. While undo_stack.c includes student.h before undo_stack.h (making Date available), any other file that includes undo_stack.h directly will encounter a compilation error. Add a forward declaration or include to make undo_stack.h self-sufficient: either add "typedef struct Date Date;" at the top or ensure Date is defined before use.

Copilot · 2026-01-28T15:51:29Z

undo_stack.h

-void add_student(list_student *list, student *new_student, UndoStack *stack); // Ajoute un étudiant à la fin de la liste.
+void add_student(hash_table *ht, list_student *list, student *new_student, UndoStack *stack);
+
+// Ajoute un étudiant à la fin de la liste.


Moving the comment to a separate line improves code readability, but consider keeping the comment on the same line as the function declaration or removing it entirely since it duplicates information from the function name and documentation.

Copilot · 2026-01-28T15:51:29Z

student.c

 }

-static void display_student_arbre(student *student) {
+void display_student_arbre(student *student) {


The change from static to non-static function visibility is inconsistent with the original design. This function was intentionally made static (file-scoped) to encapsulate implementation details. Making it public without a clear reason in the PR description may expose internal implementation details unnecessarily. Consider whether this function needs to be called from other files, and if not, keep it static.

Suggested change

void display_student_arbre(student *student) {

static void display_student_arbre(student *student) {

Copilot · 2026-01-28T15:51:30Z

hash_table.c

    if (ht == NULL || s == NULL) return;

-    unsigned int index = hash(s->CNE);
+    const unsigned int index = hash(s->CNE);


The const qualifier is added to the index variable, but index is assigned once and never modified, so this is a good practice. However, since this variable is local and immediately used, the const keyword provides minimal benefit. This is acceptable but not critical.

…lude hash_table parameter

feat: integrate hash table with student management functions

53956ba

Copilot AI review requested due to automatic review settings January 28, 2026 15:43

Copilot started reviewing on behalf of ayoubkad January 28, 2026 15:44 View session

Copilot AI reviewed Jan 28, 2026

View reviewed changes

fix: update add_student and delete_student function signatures to inc…

eaa0386

…lude hash_table parameter

ayoubkad merged commit 22c30e8 into main Jan 28, 2026

ayoubkad deleted the erreur branch March 3, 2026 02:45

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feat: integrate hash table with student management functions#2

feat: integrate hash table with student management functions#2
ayoubkad merged 2 commits intomainfrom
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	void delete_student(hash_table* ht ,list_student list, char cne_to_delete, UndoStack *stack) {
	void delete_student(hash_table ht, list_student list, char cne_to_delete, UndoStack stack) {

	delete_student(table_hachage,my_db, cne_buffer, my_stack);
	delete_student(table_hachage, my_db, cne_buffer, my_stack);

	void display_student_arbre(student *student) {
	static void display_student_arbre(student *student) {

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Pull request overview

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