Refactor c/difference-of-squares

c/difference-of-squares/src/difference_of_squares.c

@@ -1,17 +1,18 @@
 #include <stdio.h>
-#include <math.h>
 
 int square_of_sum(int n) {
-	int sum = (int) (n * ((n * 0.5) + 0.5));
-	return pow(sum, 2);
+	int sum = (n * (n + 1)) / 2;
+	return sum * sum;
 }
 
 int sum_of_squares(int n) {
-	printf("%d\n", n);
-	return n;
+	int sum = 0;
+
+	for (int i = 1; i <= n; i++) sum += i * i;
+
+	return sum;
 }
 
 int difference_of_squares(int n) {
-	printf("%d\n", n);
 	return square_of_sum(n) - sum_of_squares(n);
 }