diff --git a/Maths/Area.java b/Maths/Area.java
index 00e93e32..2faac63b 100644
--- a/Maths/Area.java
+++ b/Maths/Area.java
@@ -5,31 +5,31 @@ package Maths;
*/
public class Area {
public static void main(String[] args) {
+
/* test cube */
- assert surfaceAreaCube(1) == 6;
+ assert Double.compare(surfaceAreaCube(1), 6.0) == 0;
/* test sphere */
- assert surfaceAreaSphere(5) == 314.1592653589793;
- assert surfaceAreaSphere(1) == 12.566370614359172;
+ assert Double.compare(surfaceAreaSphere(5), 314.1592653589793) == 0;
+ assert Double.compare(surfaceAreaSphere(1), 12.566370614359172) == 0;
/* test rectangle */
- assert surfaceAreaRectangle(10, 20) == 200;
+ assert Double.compare(surfaceAreaRectangle(10, 20), 200.0) == 0;
/* test square */
- assert surfaceAreaSquare(10) == 100;
+ assert Double.compare(surfaceAreaSquare(10), 100.0) == 0;
/* test triangle */
- assert surfaceAreaTriangle(10, 10) == 50;
+ assert Double.compare(surfaceAreaTriangle(10, 10), 50.0) == 0;
/* test parallelogram */
- assert surfaceAreaParallelogram(10, 20) == 200;
+ assert Double.compare(surfaceAreaParallelogram(10, 20), 200.0) == 0;
/* test trapezium */
- assert surfaceAreaTrapezium(10, 20, 30) == 450;
+ assert Double.compare(surfaceAreaTrapezium(10, 20, 30), 450.0) == 0;
/* test circle */
- assert surfaceAreaCircle(20) == 1256.6370614359173;
-
+ assert Double.compare(surfaceAreaCircle(20), 1256.6370614359173) == 0;
}
/**
@@ -38,7 +38,7 @@ public class Area {
* @param sideLength side length of cube
* @return surface area of given cube
*/
- public static double surfaceAreaCube(double sideLength) {
+ private static double surfaceAreaCube(double sideLength) {
return 6 * sideLength * sideLength;
}
@@ -48,7 +48,7 @@ public class Area {
* @param radius radius of sphere
* @return surface area of given sphere
*/
- public static double surfaceAreaSphere(double radius) {
+ private static double surfaceAreaSphere(double radius) {
return 4 * Math.PI * radius * radius;
}
@@ -59,7 +59,7 @@ public class Area {
* @param width width of rectangle
* @return area of given rectangle
*/
- public static double surfaceAreaRectangle(double length, double width) {
+ private static double surfaceAreaRectangle(double length, double width) {
return length * width;
}
@@ -69,7 +69,7 @@ public class Area {
* @param sideLength side length of square
* @return area of given square
*/
- public static double surfaceAreaSquare(double sideLength) {
+ private static double surfaceAreaSquare(double sideLength) {
return sideLength * sideLength;
}
@@ -80,7 +80,7 @@ public class Area {
* @param height height of triangle
* @return area of given triangle
*/
- public static double surfaceAreaTriangle(double base, double height) {
+ private static double surfaceAreaTriangle(double base, double height) {
return base * height / 2;
}
@@ -91,7 +91,7 @@ public class Area {
* @param height height of parallelogram
* @return area of given parallelogram
*/
- public static double surfaceAreaParallelogram(double base, double height) {
+ private static double surfaceAreaParallelogram(double base, double height) {
return base * height;
}
@@ -103,7 +103,7 @@ public class Area {
* @param height height of trapezium
* @return area of given trapezium
*/
- public static double surfaceAreaTrapezium(double base1, double base2, double height) {
+ private static double surfaceAreaTrapezium(double base1, double base2, double height) {
return (base1 + base2) * height / 2;
}
@@ -113,7 +113,7 @@ public class Area {
* @param radius radius of circle
* @return area of given circle
*/
- public static double surfaceAreaCircle(double radius) {
+ private static double surfaceAreaCircle(double radius) {
return Math.PI * radius * radius;
}
-}
+}
\ No newline at end of file
diff --git a/Maths/PowRecursion.java b/Maths/PowRecursion.java
index 24354870..dab336b3 100644
--- a/Maths/PowRecursion.java
+++ b/Maths/PowRecursion.java
@@ -2,10 +2,10 @@ package Maths;
public class PowRecursion {
public static void main(String[] args) {
- assert pow(2, 0) == Math.pow(2, 0);
- assert pow(0, 2) == Math.pow(0, 2);
- assert pow(2, 10) == Math.pow(2, 10);
- assert pow(10, 2) == Math.pow(10, 2);
+ assert Double.compare(pow(2, 0), Math.pow(2, 0)) == 0;
+ assert Double.compare(pow(0, 2), Math.pow(0, 2)) == 0;
+ assert Double.compare(pow(2, 10), Math.pow(2, 10)) == 0;
+ assert Double.compare(pow(10, 2), Math.pow(10, 2)) == 0;
}
/**
@@ -17,10 +17,6 @@ public class PowRecursion {
* @return the value {@code a}{@code b}.
*/
public static long pow(int a, int b) {
- if (b == 0) {
- return 1;
- } else {
- return a * pow(a, b - 1);
- }
+ return b == 0 ? 1 : a * pow(a, b - 1);
}
-}
+}
\ No newline at end of file
diff --git a/Maths/SumOfArithmeticSeries.java b/Maths/SumOfArithmeticSeries.java
new file mode 100644
index 00000000..5d03c230
--- /dev/null
+++ b/Maths/SumOfArithmeticSeries.java
@@ -0,0 +1,40 @@
+package Maths;
+
+/**
+ *
+ * In mathematics, an arithmetic progression (AP) or arithmetic sequence is a sequence of numbers such that the
+ * difference between the consecutive terms is constant. Difference here means the second minus the first.
+ * For instance, the sequence 5, 7, 9, 11, 13, 15, . . . is an arithmetic progression with common difference of 2.
+ *
+ * Wikipedia: https://en.wikipedia.org/wiki/Arithmetic_progression
+ */
+public class SumOfArithmeticSeries {
+ public static void main(String[] args) {
+
+ /* 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 */
+ assert Double.compare(55.0, sumOfSeries(1, 1, 10)) == 0;
+
+ /* 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 */
+ assert Double.compare(100.0, sumOfSeries(1, 2, 10)) == 0;
+
+ /* 1 + 11 + 21 + 31 + 41 + 51 + 61 + 71 + 81 + 91 */
+ assert Double.compare(460.0, sumOfSeries(1, 10, 10)) == 0;
+
+ /* 0.1 + 0.2 + 0.3 + 0.4 + 0.5 + 0.6 + 0.7 + 0.8 + 0.9 + 1.0 */
+ assert Double.compare(5.5, sumOfSeries(0.1, 0.1, 10)) == 0;
+
+ assert Double.compare(49600.0, sumOfSeries(1, 10, 100)) == 0;
+ }
+
+ /**
+ * Calculate sum of arithmetic series
+ *
+ * @param firstTerm the initial term of an arithmetic series
+ * @param commonDiff the common difference of an arithmetic series
+ * @param numOfTerms the total terms of an arithmetic series
+ * @return sum of given arithmetic series
+ */
+ private static double sumOfSeries(double firstTerm, double commonDiff, int numOfTerms) {
+ return numOfTerms / 2.0 * (2 * firstTerm + (numOfTerms - 1) * commonDiff);
+ }
+}
\ No newline at end of file