finish hw2

HW2_182416MVEB_Tran_Vu/data.txt

-8 5
-5 4 5 0 2
-0 0 0 3 3
-2 1 3 4 3
-5 4 3 1 2
-5 5 5 1 4
-4 5 3 5 4
-4 4 3 4 5
-5 5 5 5 99
\ No newline at end of file
+10 10
+5 2 2 3 5 1 1 5 1 1
+4 3 0 2 2 0 3 1 2 0
+4 4 1 4 5 0 4 4 4 0
+1 2 5 2 2 2 2 4 1 1
+4 4 3 1 4 2 3 1 2 2
+3 2 3 5 1 1 2 1 5 2
+1 0 2 2 5 3 1 1 1 5
+5 2 1 3 3 2 2 5 2 2
+3 4 1 2 1 0 3 0 4 4
+2 1 4 3 4 3 3 3 3 5

HW2_182416MVEB_Tran_Vu/main.c → HW2_182416MVEB_Tran_Vu/homework2.c

@@ -17,51 +17,115 @@ typedef struct {
   float average;
 } student;
 
-void getArrayDimension(char*, int);
-void getStudentGrades(student*, int, int);
+/*
+ * Function:    getArrayDimension
+ * Description: get the array dimension from the text file
+ * Arguments:   output - char pointer, the output array to write to
+ *              size   - int, size of the output
+ *              data   - FILE pointer, the FILE stream pointer of the text file
+ * Return:      void
+ */
+void getArrayDimension(char*, int, FILE*);
+
+/*
+ * Function:    getStudentGrades
+ * Description: get the student grades from the file stream line by line
+ * Arguments:   studentList - student pointer, the student array output
+ *              studentsNo  - int, the number of student parsed from the file stream
+ *              coursesNo   - int, the number of courses each student have
+ *              data   - FILE pointer, the FILE stream pointer of the text file
+ * Return:      void
+ */
+void getStudentGrades(student*, int, int, FILE*);
+
+/*
+ * Function:    displayFinalMatrix
+ * Description: print the matrix to standard out
+ * Arguments:   studentList - student pointer, the list of students and their data
+ *              studentsNo  - int, the number of student parsed from the file stream
+ *              coursesNo   - int, the number of courses each student have
+ * Return:      void
+ */
 void displayFinalMatrix(student*, int, int);
+
+/*
+ * Function:    getAverage
+ * Description: calculate the average score from student type struct
+ * Arguments:   currentStudent - student, the data of the current student to calculate
+ *              coursesNo      - int, the number of courses each student have
+ * Return:      float, the average calculated
+ */
 float getAverage(student, int);
+
+/*
+ * Function:    findBestStudent
+ * Description: find the best student from all the student data array
+ * Arguments:   studentList - student pointer, the list of students and their data
+ *              studentsNo  - int, the number of student parsed from the file stream
+ * Return:      int, the ID of the best student
+ */
 int findBestStudent(student*, int);
 
 int main () {
+  //Open the stream to data.txt, with read only
+  FILE* data = fopen("data.txt", "r");
+
+  // String buffer to get the array dimension from the file stream
   char arrayDimension[20];
-  getArrayDimension(arrayDimension, 20);
+  getArrayDimension(arrayDimension, 20, data);
+
+  // Get the first value from the first line in file
   char* buff = strtok(arrayDimension, " ");
   int studentsNo = atoi(buff);
+
+  // Get the second value from the first line in file
   buff = strtok(NULL, " ");
   int coursesNo = atoi(buff);
+  if (studentsNo > 15 || coursesNo > 15 || studentsNo < 1 || coursesNo < 1) {
+    puts("Both students number and courses number cannot be bigger than 15 or smaller than 1");
+    return 1;
+  }
 
+  // Create a student type array to enter their data
   student studentList[studentsNo];
-  getStudentGrades(studentList, studentsNo, coursesNo);
+  getStudentGrades(studentList, studentsNo, coursesNo, data);
   displayFinalMatrix(studentList, studentsNo, coursesNo);
   int bestStudent = findBestStudent(studentList, studentsNo);
   printf("\nBest Student: STUDENT%0.2d\n", bestStudent + 1);
 
+  fclose(data);
   return 0;
 }
 
-void getArrayDimension(char* output, int size) {
-  FILE* data = fopen("data.txt", "r");
+void getArrayDimension(char* output, int size, FILE* data) {
+  // Get the first line of the file, which is the array dimensions
   fgets(output, sizeof(char) * size, data);
-  fclose(data);
 }
 
-void getStudentGrades(student* studentList, int studentsNo, int coursesNo) {
-  char buffer[100];
+void getStudentGrades(student* studentList, int studentsNo, int coursesNo, FILE* data) {
+  // Buffer to get text lines from the file
+  int buffLength = 100;
+  char buffer[buffLength];
+  // buffer to get each grade in the buffer string
   char* mark;
-  FILE* data = fopen("data.txt", "r");
-  fgets(buffer, sizeof(buffer), data);
 
   for (int i = 0; i < studentsNo; i++) {
-    fgets(buffer, sizeof(buffer), data);
+    // Read each lines from the array
+    fgets(buffer, buffLength, data);
+    // Divide each grade separated by " "
+    if (strlen(buffer) < coursesNo) {
+      puts("The number of students is inaccurate!");
+      exit(1);
+    }
     mark = strtok(buffer, " ");
+    // Assign the first grade to each student in the studentList array
     studentList[i].grades[0] = atoi(mark);
     for (int j = 1; j < coursesNo; j++) {
+      // Continue getting the grades and assigning them
       mark = strtok(NULL, " ");
-      studentList[i].grades[j] = atoi(mark);
+      if (mark != NULL) studentList[i].grades[j] = atoi(mark);
     }
   }
-  fclose(data);
 }
 
 void displayFinalMatrix(student* studentList, int studentsNo, int coursesNo) {
@@ -71,10 +135,12 @@ void displayFinalMatrix(student* studentList, int studentsNo, int coursesNo) {
   }
   printf("AVERAGE\n");
   for (int i = 0; i < studentsNo; i++) {
+    // For each student, we print their grades array included in their struct
     printf("  STUDENT%0.2d", i + 1);
     for (int j = 0; j < coursesNo; j++) {
       printf("\t  %d", studentList[i].grades[j]);
     }
+    // Calculate the student average based on their own grades array
     studentList[i].average = getAverage(studentList[i], coursesNo);
     printf("\t  %0.3f\n", studentList[i].average);
   }
@@ -83,8 +149,10 @@ void displayFinalMatrix(student* studentList, int studentsNo, int coursesNo) {
 float getAverage(student currentStudent, int coursesNo) {
   float total = 0;
   for (int i = 0; i < coursesNo; i++) {
+    // Add all their grades together
     total += currentStudent.grades[i];
   }
+  // Divide by the courses number to get the average
   return (float)(total / coursesNo);
 }
 
@@ -92,10 +160,12 @@ int findBestStudent(student* studentList, int studentsNo) {
   int bestStudent;
   float bestScore = -1;
   for (int i = 0; i < studentsNo; i++) {
+    // If we find a better student, bestStudent is changed
     if (studentList[i].average > bestScore) {
       bestStudent = i;
       bestScore = studentList[i].average;
     }
   }
+  // After the loop, we can safely return this is the best student
   return bestStudent;
 }

HW2_182416MVEB_Tran_Vu/makefile

+hellomake: homework2.c
+	gcc -o homework2 homework2.c