Add initial activity for egyptian fractions

Author: jcazevedo

src/main/java/com/packt/datastructuresandalg/lesson4/activity/egyptian/EgyptianFractions.java

@@ -0,0 +1,26 @@
+package com.packt.datastructuresandalg.lesson4.activity.egyptian;
+
+import java.util.List;
+
+public class EgyptianFractions {
+    public List<Long> build(Long numerator, Long denominator) { return null; }
+
+    public static void printResult(Long numerator, Long denominator) {
+        EgyptianFractions fractions = new EgyptianFractions();
+        List<Long> ds = fractions.build(numerator, denominator);
+        System.out.print(numerator + "/" + denominator + " =");
+        for (int i = 0; i < ds.size(); i++) {
+            System.out.print(" 1/" + ds.get(i));
+            if (i + 1 < ds.size())
+                System.out.print(" +");
+            else
+                System.out.print("\n");
+        }
+    }
+
+    public static void main(String[] args) {
+        printResult(2l, 3l);
+        printResult(6l, 14l);
+        printResult(12l, 13l);
+    }
+}

src/main/java/com/packt/datastructuresandalg/lesson4/activity/egyptian/solution/EgyptianFractions.java

@@ -0,0 +1,41 @@
+package com.packt.datastructuresandalg.lesson4.activity.egyptian.solution;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class EgyptianFractions {
+    public List<Long> build(Long numerator, Long denominator) {
+        if (numerator == 0 || denominator == 0)
+            return new ArrayList<>();
+
+        if (denominator % numerator == 0) {
+            List<Long> l = new ArrayList<>();
+            l.add(denominator / numerator);
+            return l;
+        }
+
+        Long n = denominator / numerator + 1;
+        List<Long> r = build(numerator * n - denominator, denominator * n);
+        r.add(n);
+        return r;
+    }
+
+    public static void printResult(Long numerator, Long denominator) {
+        EgyptianFractions fractions = new EgyptianFractions();
+        List<Long> ds = fractions.build(numerator, denominator);
+        System.out.print(numerator + "/" + denominator + " =");
+        for (int i = 0; i < ds.size(); i++) {
+            System.out.print(" 1/" + ds.get(i));
+            if (i + 1 < ds.size())
+                System.out.print(" +");
+            else
+                System.out.print("\n");
+        }
+    }
+
+    public static void main(String[] args) {
+        printResult(2l, 3l);
+        printResult(6l, 14l);
+        printResult(12l, 13l);
+    }
+}