Add answers for problem 2

include/p2.h

@@ -0,0 +1,8 @@
+#ifndef P2_H
+#define P2_H
+
+void find_avg_min_max(double* arr, int size,
+		      double* out_avg, double* out_min, double* out_max);
+
+#endif
+

src/main.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
 
 #include "p1.h"
+#include "p2.h"
 
 int main(void) {
 	// Problem 1
@@ -8,6 +9,17 @@ int main(void) {
 	printf("Number of alphanumeric characters in \"Hello World!!\": %d\n", num_alphanum);
 
 	// Problem 2
+	double arr[8] = {
+		2.5, 4.3, 8.1, -7.4, 2.0, 1.0, 3.0, 4.0
+	};
+
+	double avg = 0;
+	double min = 0;
+	double max = 0;
+
+	find_avg_min_max(arr, 8, &avg, &min, &max);
+
+	printf("Average: %.2lf, Min: %.2lf, Max: %.2lf\n", avg, min, max);
 
 	return 0;
 }

src/p2.c

@@ -0,0 +1,32 @@
+#include "p2.h"
+
+void find_avg_min_max(double* arr, int size,
+                      double* out_avg, double* out_min, double* out_max) {
+	// If there are no elements in the array, attempting to access the first
+	// element to initialize min and max will access memory outside the bounds
+	// of the array. Instead, we will return early.
+	if (size <= 0) {
+		return;
+	}
+
+	double sum = 0;
+	double min = arr[0];
+	double max = arr[0];
+
+	for (int i = 0; i < size; ++i) {
+		sum += arr[i];
+
+		if (arr[i] < min) {
+			min = arr[i];
+		}
+
+		if (arr[i] > max) {
+			max = arr[i];
+		}
+	}
+
+	*out_avg = sum / size;
+	*out_min = min;
+	*out_max = max;
+}
+