diff --git a/src/main/java/com/thealgorithms/Recursion/FibonacciSeries.java b/src/main/java/com/thealgorithms/Recursion/FibonacciSeries.java new file mode 100644 index 000000000000..a89d110b8da3 --- /dev/null +++ b/src/main/java/com/thealgorithms/Recursion/FibonacciSeries.java @@ -0,0 +1,21 @@ +package com.thealgorithms.Recursion; + +/* + The Fibonacci series is a sequence of numbers where each number is the sum of the two preceding ones, + starting with 0 and 1. + NUMBER 0 1 2 3 4 5 6 7 8 9 10 ... + FIBONACCI 0 1 1 2 3 5 8 13 21 34 55 ... +*/ + +public final class FibonacciSeries { + private FibonacciSeries() { + throw new UnsupportedOperationException("Utility class"); + } + public static int fibonacci(int n) { + if (n <= 1) { + return n; + } else { + return fibonacci(n - 1) + fibonacci(n - 2); + } + } +} diff --git a/src/test/java/com/thealgorithms/Recursion/FibonacciSeriesTest.java b/src/test/java/com/thealgorithms/Recursion/FibonacciSeriesTest.java new file mode 100644 index 000000000000..4e4fc45809ba --- /dev/null +++ b/src/test/java/com/thealgorithms/Recursion/FibonacciSeriesTest.java @@ -0,0 +1,27 @@ +package com.thealgorithms.Recursion; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import org.junit.jupiter.api.Test; + +public class FibonacciSeriesTest { + + @Test + public void testFibonacci() { + assertEquals(0, FibonacciSeries.fibonacci(0)); + assertEquals(1, FibonacciSeries.fibonacci(1)); + assertEquals(1, FibonacciSeries.fibonacci(2)); + assertEquals(2, FibonacciSeries.fibonacci(3)); + assertEquals(3, FibonacciSeries.fibonacci(4)); + assertEquals(5, FibonacciSeries.fibonacci(5)); + assertEquals(8, FibonacciSeries.fibonacci(6)); + assertEquals(13, FibonacciSeries.fibonacci(7)); + assertEquals(21, FibonacciSeries.fibonacci(8)); + assertEquals(34, FibonacciSeries.fibonacci(9)); + assertEquals(55, FibonacciSeries.fibonacci(10)); + assertEquals(89, FibonacciSeries.fibonacci(11)); + assertEquals(144, FibonacciSeries.fibonacci(12)); + assertEquals(233, FibonacciSeries.fibonacci(13)); + assertEquals(377, FibonacciSeries.fibonacci(14)); + } +}