Java solutions for week 136

3 files changed, 86 insertions, 0 deletions

diff --git a/challenge-136/abigail/README.md b/challenge-136/abigail/README.md
index ecd34dfa17..3989f056f3 100644
--- a/challenge-136/abigail/README.md
+++ b/challenge-136/abigail/README.md
@@ -7,6 +7,7 @@
 * [Bc](bc/ch-1.bc)
 * [C](c/ch-1.c)
 * [Go](go/ch-1.go)
+* [Java](java/ch-1.java)
 * [Lua](lua/ch-1.lua)
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
@@ -21,6 +22,7 @@
 * [Bc](bc/ch-2.bc)
 * [C](c/ch-2.c)
 * [Go](go/ch-2.go)
+* [Java](java/ch-2.java)
 * [Lua](lua/ch-2.lua)
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
diff --git a/challenge-136/abigail/java/ch-1.java b/challenge-136/abigail/java/ch-1.java
new file mode 100644
index 0000000000..4fbc1db180
--- /dev/null
+++ b/challenge-136/abigail/java/ch-1.java
@@ -0,0 +1,55 @@
+//
+// See ../README.md
+//
+
+//
+// Run as: ln ch-1.java ch1.java; javac ch1.java; java ch1 < input-file
+//
+
+import java.util.*;
+
+public class ch1 {
+    //
+    // Find the GCD, using Stein's algorithm
+    //    (https://en.wikipedia.org/wiki/Binary_GCD_algorithm)
+    //
+    public static int gcd (int u, int v) {
+        boolean u_odd = u % 2 != 0;
+        boolean v_odd = v % 2 != 0;
+
+        return u == v || v == 0 ? u
+             :           u == 0 ? v
+             : !u_odd && !v_odd ? gcd (u >> 1, v >> 1) << 1
+             : !u_odd &&  v_odd ? gcd (u >> 1, v)
+             :  u_odd && !v_odd ? gcd (u,      v >> 1)
+             :  u     >   v     ? gcd (u - v, v)
+             :                    gcd (v - u, u);
+    }
+
+    //
+    // Return true if number is a power of n, that is, number == n ^ p
+    // for some non-negative integer p. Return false otherwise.
+    //
+    public static boolean is_power_of_n (int number, int n) {
+        return number <  1     ? false
+             : number == 1     ? true
+             : number % n != 0 ? false
+             : is_power_of_n (number / n, n);
+    }
+
+    public static boolean is_power_of_2 (int number) {
+        return is_power_of_n (number, 2);
+    }
+
+    public static void main (String [] args) {
+        Scanner scanner = new Scanner (System . in);
+        while (scanner . hasNextInt ()) {
+            int n = scanner . nextInt ();
+            int m = scanner . nextInt ();
+
+            int r = gcd (n, m);
+
+            System . out . println (r > 1 && is_power_of_2 (r) ? 1 : 0);
+        }
+    }
+}
diff --git a/challenge-136/abigail/java/ch-2.java b/challenge-136/abigail/java/ch-2.java
new file mode 100644
index 0000000000..f08384cf95
--- /dev/null
+++ b/challenge-136/abigail/java/ch-2.java
@@ -0,0 +1,29 @@
+//
+// See ../README.md
+//
+
+//
+// Run as: ln ch-2.java ch2.java; javac ch2.java; java ch2 < input-file
+//
+
+import java.util.*;
+
+public class ch2 {
+    public static int count (int target, int this_fib, int prev_fib) {
+        return target <  this_fib ? 0
+             : target == this_fib ? 1
+             : count (target - this_fib, this_fib + prev_fib, this_fib) +
+               count (target,            this_fib + prev_fib, this_fib);
+    }
+
+    public static int count (int target) {
+        return count (target, 1, 1);
+    }
+
+    public static void main (String [] args) {
+        Scanner scanner = new Scanner (System . in);
+        while (scanner . hasNextInt ()) {
+            System . out . println (count (scanner . nextInt ()));
+        }
+    }
+}