From 332bebc151a8b986f2fabb160e838e6d02a2d9d0 Mon Sep 17 00:00:00 2001
From: Gabriel Barker <gbarker@financialforce.com>
Date: Fri, 11 Oct 2019 16:46:00 +0100
Subject: [PATCH 1/3] Add jumpSearch algorithm

---
 src/_Searching_/JumpSearch/index.js | 31 +++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 src/_Searching_/JumpSearch/index.js

diff --git a/src/_Searching_/JumpSearch/index.js b/src/_Searching_/JumpSearch/index.js
new file mode 100644
index 00000000..dd0761aa
--- /dev/null
+++ b/src/_Searching_/JumpSearch/index.js
@@ -0,0 +1,31 @@
+function jumpSearch(arr, jump, key) {
+    // treat jumps larger than array size as linear search
+    jump = jump > arr.length ? 1 : jump;
+
+    let low = 0, high = 0;
+    for (let i = jump; i < arr.length; i+=jump) {
+        if(key < arr[i]) {
+            high = i;
+            low = i - jump;
+            break;
+        }
+    }
+
+    // check if loop has finished without finding key
+    if(high == 0) {
+        high = arr.length;
+        low = high - jump;
+    }
+
+    for(let i = low; i < high; i++) {
+        if(arr[i] == key) {
+            // return the index of the key
+            return i + 1;
+        }
+    }
+    return null;
+  }
+  
+  module.exports = {
+    jumpSearch,
+  };
\ No newline at end of file

From 9f8fabeb371e660401549f33cc1bffb31b235e1a Mon Sep 17 00:00:00 2001
From: Gabriel Barker <gbarker@financialforce.com>
Date: Fri, 11 Oct 2019 17:12:16 +0100
Subject: [PATCH 2/3] Test jumpSeach method

---
 src/_Searching_/JumpSearch/JumpSearch.test.js | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 src/_Searching_/JumpSearch/JumpSearch.test.js

diff --git a/src/_Searching_/JumpSearch/JumpSearch.test.js b/src/_Searching_/JumpSearch/JumpSearch.test.js
new file mode 100644
index 00000000..18988dc4
--- /dev/null
+++ b/src/_Searching_/JumpSearch/JumpSearch.test.js
@@ -0,0 +1,26 @@
+const { jumpSearch, jumpSearchRecursive } = require('.');
+
+describe('Jump Search', () => {
+    const array = [1, 2, 3, 4, 5, 6, 7, 8];
+    const jump = 3;
+    describe('When element to find is at 1st position ', () => {
+        it('Jump search', () => {
+          expect(jumpSearch(array, jump, 1)).toEqual(0);
+        });
+      });
+    describe('When element to find is at last position ', () => {
+        it('Jump search', () => {
+          expect(jumpSearch(array, jump, 7)).toEqual(6);
+        });
+      });
+    describe('When element to find is at random position ', () => {
+        it('Jump search', () => {
+          expect(jumpSearch(array, jump, 3)).toEqual(2);
+        });
+      });
+    describe('When jump is larger than array', () => {
+        it('Jump search', () => {
+          expect(jumpSearch(array, 9, 3)).toEqual(2);
+        });
+      });
+});
\ No newline at end of file

From ce484cd416890800e0f5867f566be98b3ca75c29 Mon Sep 17 00:00:00 2001
From: Gabriel Barker <gbarker@financialforce.com>
Date: Fri, 11 Oct 2019 17:16:14 +0100
Subject: [PATCH 3/3] fix minor error

---
 src/_Searching_/JumpSearch/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/_Searching_/JumpSearch/index.js b/src/_Searching_/JumpSearch/index.js
index dd0761aa..cf2699ce 100644
--- a/src/_Searching_/JumpSearch/index.js
+++ b/src/_Searching_/JumpSearch/index.js
@@ -20,7 +20,7 @@ function jumpSearch(arr, jump, key) {
     for(let i = low; i < high; i++) {
         if(arr[i] == key) {
             // return the index of the key
-            return i + 1;
+            return i;
         }
     }
     return null;