Adding Compound Interest

src/main/java/com/williamfiset/algorithms/math/CompoundInterest.java

@@ -0,0 +1,14 @@
+package com.williamfiset.algorithms.math;
+
+public class CompoundInterest {
+    public static double CompoundInterest(double principalAmount, double interestRateDecimal, double compoundsPerYear, double totalYears) {
+        double unroundedNum = (principalAmount * Math.pow((1+(interestRateDecimal/compoundsPerYear)),compoundsPerYear*totalYears));
+        //rounds to the nearest cent
+        return Math.round(unroundedNum*100.00)/100.00;
+    }
+    public static void main(String[] args) {
+        //example cases
+        System.out.println(CompoundInterest(100,0.12,12,2));
+        System.out.println(CompoundInterest(2001,0.21,4,8));
+    }
+}

src/test/java/com/williamfiset/algorithms/math/CompoundInterestTest.java

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+package com.williamfiset.algorithms.math;
+
+import org.junit.Test;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.util.*;
+
+public class CompoundInterestTest {
+    @Test
+    //example tests
+    public void testInterest() {
+        assertThat(CompoundInterest.CompoundInterest(120,0.1,12,2)).isEqualTo(146.45);
+        assertThat(CompoundInterest.CompoundInterest(.5,0.25,4,12)).isEqualTo(9.18);
+        assertThat(CompoundInterest.CompoundInterest(12000,0.05,1,5)).isEqualTo(15315.38);
+        assertThat(CompoundInterest.CompoundInterest(10,0.1,2,10)).isEqualTo(26.53);
+    }
+}