Reworked exercise 0 of homework1.cpp

1 files changed, 43 insertions, 52 deletions

diff --git a/Year 1/Programming introduction/Homeworks/homework1.cpp b/Year 1/Programming introduction/Homeworks/homework1.cpp
index 562ec4e..1a3d069 100644
--- a/Year 1/Programming introduction/Homeworks/homework1.cpp
+++ b/Year 1/Programming introduction/Homeworks/homework1.cpp
@@ -10,16 +10,16 @@ using namespace std;
 
 /* Floating point arithmetic */
 
-double const FLOAT_EPSILON_FLOOR = 0.0001, FLOAT_EPSILON_CEIL = FLOAT_EPSILON_FLOOR * 9;
+double const FLOAT_EPSILON = 0.001;
 
 bool eq(double a, double b)
 {
-	return ((a - b) < 0.0 ? (b - a) : (a - b)) <= FLOAT_EPSILON_FLOOR;
+	return ((a - b) < 0.0 ? (b - a) : (a - b)) < FLOAT_EPSILON;
 }
 
 bool lt(double a, double b)
 {
-	return !eq(a, b) && (a - b) < FLOAT_EPSILON_CEIL;
+	return !eq(a, b) && (a - b) < FLOAT_EPSILON;
 }
 
 bool mt(double a, double b)
@@ -29,75 +29,66 @@ bool mt(double a, double b)
 
 /* Planimetry */
 
-double distanceBetweenPoints(int x1, int y1, int x2, int y2)
+double distanceBetweenPoints(double x1, double y1, double x2, double y2)
 {
-	int sideA = x1 - x2, sideB = y1 - y2;
+	double 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
-	// The coordinates of points B, C, D and E are some combination of positive and/or negative values of 2.828
+void printPointLocation(double x, double y) {
+	// The coordinates of points B, C, D and E are some combination of positive and/or negative values of 2.828,
+	// because BC and DE make 45 degrees angle with the abscissa
 	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;
+				SLOPE_BC =  CROSS_PNT / CROSS_PNT,
+				SLOPE_DE = -CROSS_PNT / CROSS_PNT;
+	char const NOWHERE[] = "Nowhere!";
 
-	double x, y;
-	cin >> x >> y;
-
-	if (eq(x, 0)) // if it's on the Y ordinate
-	{
-		cout << "On a line" << endl;
-	}
+	if (eq(x, 0))
+		cout << NOWHERE << endl; // On a line
 	else if (lt(distanceBetweenPoints(0, 0, x, y), 4.0))
 	{
 		double pointSlope = y / x;
 
-		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))
+		// Brackets in some places for improved readability
+		if (eq(x, -CROSS_PNT) || eq(x, CROSS_PNT) || eq(pointSlope, SLOPE_BC) || (eq(pointSlope, SLOPE_DE) && mt(y, 0)))
 		{
-			cout << "On a line" << endl;
+			cout << NOWHERE << endl; // On a line
 		}
-		else if ((mt(y, 0) || eq(y, 0)) && mt(x, 0)) // Check 1st quadrant
+		else if (mt(pointSlope, SLOPE_BC))
 		{
-			if (mt(pointSlope, SLOPE_B))
-				cout << "Inside green area!" << endl;
-			else if (mt(x, CROSS_PNT))
-				cout << "Inside purple area!" << endl;
-			else
-				cout << "Inside yellow area!" << endl;
+			cout << "Inside " << ((x > 0) ? "green" : "blue" ) << " area!" << endl;
 		}
-		else if ((mt(y, 0) || eq(y, 0)) && lt(x, 0)) // Check 2nd quadrant
+		else if (lt(pointSlope, SLOPE_DE) && x < 0)
 		{
-			if (lt(pointSlope, SLOPE_D))
-				cout << "Inside red area!" << endl;
-			else if (x > -CROSS_PNT)
-				cout << "Inside pink area!" << endl;
+			cout << "Inside red area!" << endl;
 		}
-		else if (lt(y, 0) && lt(x, 0)) // Check 3rd quadrant
+		else if (mt(x, CROSS_PNT))
 		{
-			if (mt(pointSlope, SLOPE_C))
-				cout << "Inside blue area!" << endl;
-			else if (mt(x, -CROSS_PNT))
-				cout << "Inside pink area!" << endl;
+			cout << "Inside purple area!" << endl;
 		}
-		else // Check 4th quadrant
+		else if (mt(x, -CROSS_PNT) && x < 0)
 		{
-			if (mt(pointSlope, SLOPE_E) && mt(x, CROSS_PNT))
-				cout << "Inside purple area!" << endl;
-			else
-				cout << "Inside yellow area!" << endl;
+			cout << "Inside pink area!" << endl;
 		}
+		else if (x > 0)
+			cout << "Inside yellow area!" << endl;
+		else
+			cout << NOWHERE << endl;
 	}
-	else if ((lt(-2, x) && lt(x, 2)) && (lt(-6, y) && lt(y, -7))) // Outside circle and in rectangle
-	{
-		cout << "Inside grey area" << endl;
-	}
+	else if (lt(-2, x) && lt(x, 2) && mt(-6, y) && mt(y, -7))
+		cout << "Inside grey area!" << endl;
+	else
+		cout << NOWHERE << endl;
+}
+
+/* Exercise calculations */
+
+void ex0()
+{
+	double x, y;
+	cin >> x >> y;
+
+	printPointLocation(x, y);
 }
 
 /*
@@ -327,5 +318,5 @@ void ex4()
 
 int main()
 {
-	ex1();
+	ex0();
 }