From 56e887213bffa683cd89501c6726c6135b09b2cd Mon Sep 17 00:00:00 2001
From: shellhub <shellhub.me@gmail.com>
Date: Wed, 23 Oct 2019 21:42:04 +0800
Subject: [PATCH 1/2] add pow

---
 Maths/Pow.java          | 26 ++++++++++++++++++++++++++
 Maths/PowRecursion.java | 26 ++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 Maths/Pow.java
 create mode 100644 Maths/PowRecursion.java

diff --git a/Maths/Pow.java b/Maths/Pow.java
new file mode 100644
index 00000000..605e01d9
--- /dev/null
+++ b/Maths/Pow.java
@@ -0,0 +1,26 @@
+package maths;
+
+public class Pow {
+    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);
+    }
+
+    /**
+     * Returns the value of the first argument raised to the power of the
+     * second argument
+     *
+     * @param a the base.
+     * @param b the exponent.
+     * @return the value {@code a}<sup>{@code b}</sup>.
+     */
+    public static long pow(int a, int b) {
+        long result = 1;
+        for (int i = 1; i <= b; i++) {
+            result *= a;
+        }
+        return result;
+    }
+}
diff --git a/Maths/PowRecursion.java b/Maths/PowRecursion.java
new file mode 100644
index 00000000..673b8fde
--- /dev/null
+++ b/Maths/PowRecursion.java
@@ -0,0 +1,26 @@
+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);
+    }
+
+    /**
+     * Returns the value of the first argument raised to the power of the
+     * second argument
+     *
+     * @param a the base.
+     * @param b the exponent.
+     * @return the value {@code a}<sup>{@code b}</sup>.
+     */
+    public static long pow(int a, int b) {
+        int result = 1;
+        for (int i = 1; i <= b; i++) {
+            result *= a;
+        }
+        return result;
+    }
+}

From d11b7347b650c225e31b1d46ec0f8800a8ce1fd9 Mon Sep 17 00:00:00 2001
From: shellhub <shellhub.me@gmail.com>
Date: Thu, 24 Oct 2019 11:54:37 +0800
Subject: [PATCH 2/2] using recursion

---
 Maths/PowRecursion.java | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Maths/PowRecursion.java b/Maths/PowRecursion.java
index 673b8fde..24354870 100644
--- a/Maths/PowRecursion.java
+++ b/Maths/PowRecursion.java
@@ -17,10 +17,10 @@ public class PowRecursion {
      * @return the value {@code a}<sup>{@code b}</sup>.
      */
     public static long pow(int a, int b) {
-        int result = 1;
-        for (int i = 1; i <= b; i++) {
-            result *= a;
+        if (b == 0) {
+            return 1;
+        } else {
+            return a * pow(a, b - 1);
         }
-        return result;
     }
 }