Add problem 8 solution

include/p8.h

@@ -0,0 +1,18 @@
+#ifndef P8_H
+#define P8_H
+
+// 8.a
+
+typedef struct {
+	int id;
+	char first_name[16];
+	char last_name[16];
+	double gpa;
+} Student;
+
+void prompt_student_info(Student* out_student);
+void print_student(Student* student);
+double compute_average_gpa(Student* students, int num_students);
+
+#endif
+

src/main.c

@@ -7,6 +7,7 @@
 #include "p5.h"
 #include "p6.h"
 #include "p7.h"
+#include "p8.h"
 
 void print_int_arr(int* arr, int size) {
 	for (int i = 0; i < size; ++i) {
@@ -77,6 +78,23 @@ int main(void) {
 	reverse_string(p7_str);
 	printf("\"%s\"\n", p7_str);
 
+	// Problem 8
+	printf("Problem 8:\n");
+
+	Student students[5];
+
+	for (int i = 0; i < 5; ++i) {
+		prompt_student_info(&students[i]);
+	}
+
+	for (int i = 0; i < 5; ++i) {
+		print_student(&students[i]);
+	}
+
+	double average_gpa = compute_average_gpa(students, 5);
+
+	printf("Average GPA: %.2lf\n", average_gpa);
+
 	return 0;
 }
 

src/p8.c

@@ -0,0 +1,40 @@
+#include "p8.h"
+
+#define _CRT_SECURE_NO_WARNINGS
+
+#include <stdio.h>
+
+void prompt_student_info(Student* out_student) {
+	printf("Enter student ID: ");
+	scanf("%d", &out_student->id);
+
+	printf("Enter student first name: ");
+	// Our array can only hold 16 characters including the null terminator,
+	// so we can only read 15 non-null characters. Consider what happens
+	// to any remaining characters if the user enters a string longer than
+	// 15 characters.
+	scanf("%15s", out_student->first_name);
+
+	printf("Enter student last name: ");
+	// Same as first name
+	scanf("%15s", out_student->last_name);
+
+	printf("Enter student GPA: ");
+	scanf("%lf", &out_student->gpa);
+}
+
+void print_student(Student* student) {
+	printf("%8d%16s%16s%8.2lf\n", student->id, student->first_name,
+	       student->last_name, student->gpa);
+}
+
+double compute_average_gpa(Student* students, int num_students) {
+	double gpa_sum = 0.0;
+
+	for (int i = 0; i < num_students; ++i) {
+		gpa_sum += students[i].gpa;
+	}
+
+	return gpa_sum / num_students;
+}
+