Fixed read file missing statement

data/students.test.txt

@@ -5,4 +5,16 @@ Computer
 88
 98
 52
-95
+95
+Sambo
+12345
+CS90
+2
+50
+40
+Chea
+6789
+CS78
+2
+50
+20

work1/single.c

@@ -34,12 +34,17 @@ typedef struct person_tag PERSON;
 typedef struct course_tag COURSE;
 typedef struct student_tag STUDENT;
 
+// file function
+void read_file();
+
 // util functions
 void display_menu();
 void print_welcome();
 void print_student(STUDENT *student);
 void release(STUDENT *data);
+int find_min_in_array(int *array);
 STUDENT *search_student_by_name_or_id(char search_key[NAME_SIZE]);
+STUDENT *find_maximum_avg();
 
 // core functions
 void display_students();
@@ -47,7 +52,6 @@ void search_student();
 void find_maximum();
 void find_failed();
 void update_file();
-void read_file();
 void quite();
 
 // Linked list functions
@@ -234,6 +238,9 @@ void search_student()
 
 STUDENT *search_student_by_name_or_id(char search_key[NAME_SIZE])
 {
+    // refresh data from file first
+    read_file();
+
     STUDENT *temp = head;
 
     while (temp != NULL)
@@ -249,14 +256,118 @@ STUDENT *search_student_by_name_or_id(char search_key[NAME_SIZE])
     return NULL;
 }
 
+STUDENT *find_maximum_avg()
+{
+    // refresh data from file first
+    read_file();
+
+    STUDENT *temp = head, *max;
+    max = temp->next;
+
+    while (temp != NULL)
+    {
+        if (max == NULL)
+        {
+            return temp;
+        }
+
+        if (max->course_info.avg < temp->course_info.avg)
+        {
+            max = temp;
+        }
+
+        temp = temp->next;
+    }
+
+    // release the max next record
+    // set max next element to NULL
+    // because we use only one record
+    release(max->next);
+    max->next = NULL;
+
+    return max;
+}
+
+int find_min_in_array(int *array)
+{
+    if (array == NULL)
+    {
+        return -1;
+    }
+
+    int min = array[0];
+    size_t size = sizeof(array) / sizeof(array[0]);
+
+    for (int i = 1; i < size; i++)
+    {
+        if (array[i] < min)
+        {
+            min = array[i];
+        }
+    }
+    return min;
+}
+
+STUDENT *find_failed_mark(int upper_mark)
+{
+    // refresh data from file first
+    read_file();
+
+    STUDENT *temp = head, *failed_students = NULL;
+
+    while (temp != NULL)
+    {
+        int min = find_min_in_array(temp->course_info.marks);
+
+        if (min < upper_mark)
+        {
+            if (failed_students == NULL)
+            {
+                failed_students = temp;
+                failed_students->next = NULL;
+            }
+            else
+            {
+                while (failed_students->next != NULL)
+                {
+                    failed_students = failed_students->next;
+                }
+                failed_students->next = temp;
+            }
+        }
+        temp = temp->next;
+    }
+
+    return failed_students;
+}
 void find_maximum()
 {
-    printf("\nNot implement yet!");
+    // refresh data from file first
+    read_file();
+
+    STUDENT *max_student = find_maximum_avg();
+    if (max_student == NULL)
+    {
+        printf("\nNo maximum student found!\n");
+        return;
+    }
+
+    printf("\nFind maximum avg was found with: %0.2f\n", max_student->course_info.avg);
+    print_student(max_student);
 }
 
 void find_failed()
 {
-    printf("\nNot implement yet!");
+    int upper_mark = 50;
+    STUDENT *failed_students = find_failed_mark(upper_mark);
+    if (failed_students == NULL)
+    {
+        printf("\nNo failed student found!\n");
+        return;
+    }
+
+    printf("\nFind the failed students that at least one mark less than %d\n", upper_mark);
+    print_student(failed_students);
 }
 
 void update_file()
@@ -317,7 +428,7 @@ again:
 
     fclose(file);
 
-    printf("\nSaved");
+    printf("\nRecord saved successfully!");
 
     // reload data into linked list again
     read_file();