Added comments and moved number to constant in ex0 homework1.cpp

1 files changed, 17 insertions, 9 deletions

diff --git a/Year 1/Programming introduction/Homeworks/homework1.cpp b/Year 1/Programming introduction/Homeworks/homework1.cpp
index b0eed83..0ae657c 100644
--- a/Year 1/Programming introduction/Homeworks/homework1.cpp
+++ b/Year 1/Programming introduction/Homeworks/homework1.cpp
@@ -8,6 +8,8 @@ using namespace std;
  * Exercise 0
  */
 
+/* Floating point arithmetic */
+
 double const FLOAT_EPSILON_FLOOR = 0.0001, FLOAT_EPSILON_CEIL = FLOAT_EPSILON_FLOOR * 9;
 
 bool eq(double a, double b) {
@@ -22,18 +24,24 @@ bool mt(double a, double b) {
 	return lt(b, a);
 }
 
+/* Planimetry */
+
 double distanceBetweenPoints(int x1, int y1, int x2, int y2)
 {
 	int sideA = x1 - x2, sideB = y1 - y2;
 	return sqrt(sideA * sideA + sideB * sideB); // Pythagorean theorem
 }
 
+/* Exercise calculations */
+
 void ex0() {
 	// These should be precalculated, but this shows how they're found out
-	float const SLOPE_B =  2.828 /  2.828,
-				SLOPE_C = -2.828 / -2.828,
-				SLOPE_D = -2.828 /  2.828,
-				SLOPE_E =  2.828 / -2.828;
+	// The coordinates of points B, C, D and E are some combination of positive and/or negative values of 2.828
+	float const CROSS_PNT = 2.828,
+				SLOPE_B =  CROSS_PNT /  CROSS_PNT,
+				SLOPE_C = -CROSS_PNT / -CROSS_PNT,
+				SLOPE_D = -CROSS_PNT /  CROSS_PNT,
+				SLOPE_E =  CROSS_PNT / -CROSS_PNT;
 
 	double x, y;
 	cin >> x >> y;
@@ -43,12 +51,12 @@ void ex0() {
 	else if (lt(distanceBetweenPoints(0, 0, x, y), 4.0)) {
 		double pointSlope = y / x;
 
-		if (eq(x, -2.828) || eq(x, 2.828) || eq(pointSlope, SLOPE_B) || eq(pointSlope, SLOPE_C) || eq(pointSlope, SLOPE_D) || eq(pointSlope, SLOPE_E))
+		if (eq(x, -CROSS_PNT) || eq(x, CROSS_PNT) || eq(pointSlope, SLOPE_B) || eq(pointSlope, SLOPE_C) || eq(pointSlope, SLOPE_D) || eq(pointSlope, SLOPE_E))
 			cout << "On a line" << endl;
 		else if ((mt(y, 0) || eq(y, 0)) && mt(x, 0)) { // Check 1st quadrant
 			if (mt(pointSlope, SLOPE_B))
 				cout << "Inside green area!" << endl;
-			else if (mt(x, 2.828))
+			else if (mt(x, CROSS_PNT))
 				cout << "Inside purple area!" << endl;
 			else
 				cout << "Inside yellow area!" << endl;
@@ -56,17 +64,17 @@ void ex0() {
 		else if ((mt(y, 0) || eq(y, 0)) && lt(x, 0)) { // Check 2nd quadrant
 			if (lt(pointSlope, SLOPE_D))
 				cout << "Inside red area!" << endl;
-			else if (x > -2.828)
+			else if (x > -CROSS_PNT)
 				cout << "Inside pink area!" << endl;
 		}
 		else if (lt(y, 0) && lt(x, 0)) { // Check 3rd quadrant
 			if (mt(pointSlope, SLOPE_C))
 				cout << "Inside blue area!" << endl;
-			else if (mt(x, -2.828))
+			else if (mt(x, -CROSS_PNT))
 				cout << "Inside pink area!" << endl;
 		}
 		else { // Check 4th quadrant
-			if (mt(pointSlope, SLOPE_E) && mt(x, 2.828))
+			if (mt(pointSlope, SLOPE_E) && mt(x, CROSS_PNT))
 				cout << "Inside purple area!" << endl;
 			else
 				cout << "Inside yellow area!" << endl;