Merge pull request #16 from dieterpl/master

abranhe · web-flow · commit 454682b74afa · 2018-10-10T22:12:53.000-04:00
Added fibonacci search
diff --git a/allalgorithms/searches/__init__.py b/allalgorithms/searches/__init__.py
@@ -1,2 +1,3 @@
 from .binary_search import *
+from .fibonacci_search import *
 from .jump_search import *
diff --git a/allalgorithms/searches/fibonacci_search.py b/allalgorithms/searches/fibonacci_search.py
@@ -0,0 +1,35 @@
+# -*- coding: UTF-8 -*-
+#
+# Fibonacci search works for a sorted array.
+# The All ▲lgorithms library for python
+#
+# Contributed by: dieterpl
+# Github: @dieterpl
+#
+
+
+def fibonacci_search(arr, query):
+    fib2, fib1 = 0, 1
+    fib = fib2 + fib1
+    hi = len(arr) - 1
+    while fib <= hi:
+        fib2 = fib1
+        fib1 = fib
+        fib = fib2 + fib1
+    offset = -1
+    while fib > 1:
+        i = min(offset + fib2, hi)
+        if arr[i] < query:
+            fib = fib1
+            fib1 = fib2
+            fib2 = fib - fib1
+            offset = i
+        elif arr[i] > query:
+            fib = fib2
+            fib1 = fib1 - fib2
+            fib2 = fib - fib1
+        else:
+            return i
+    if fib1 and arr[offset + 1] == query:
+        return offset + 1
+    return None
diff --git a/changelog.md b/changelog.md
@@ -8,11 +8,12 @@ Date: October 9, 2018
 
 ### Algorithms:
 
-- ### Sorting
-  - Bubble Sort
 - ### Searches
   - Merge Sort
 
+- ### Sorting
+  - Bubble Sort
+  
 # Version `0.0.1`
 
 Date: TO ADDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD, 2018
@@ -22,10 +23,13 @@ Date: TO ADDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD, 2018
 Added:
 
 - ### Searches
+  - Fibonacci Search
+  - Jump Search
+
+- ### Sorting
   - Bubble Sort
   - Cocktail Shaker Sort
   - Insertion Sort
   - Pigeonhole Sort
   - Selection Sort
-  - Stooge Sort
-  - Jump Search
+  - Stooge Sort
diff --git a/docs/readme.md b/docs/readme.md
@@ -59,6 +59,7 @@ print(binary_search(arr, 3))
 
 - ### Searches
   - [Binary Search](searches/binary-search)
+  - [Fibonacci Search](searches/fibonacci-search)
   - [Jump Search](searches/jump-search)
 - ### Sorting
   - [Bubble Sort](sorting/bubble-sort)
diff --git a/docs/searches/fibonacci-search.md b/docs/searches/fibonacci-search.md
@@ -0,0 +1,33 @@
+# Fibonacci Search
+
+In computer science, the Fibonacci search technique is a method of searching a sorted array using a divide and conquer algorithm that narrows down possible locations with the aid of Fibonacci numbers. (Wikipedia)
+## Install
+
+```
+pip install allalgorithms
+```
+
+## Usage
+
+```py
+from allalgorithms.searches import fibonacci_search
+
+arr = [-2, 1, 2, 7, 10, 77]
+
+print(fibonacci_search(arr, 7))
+# -> 3
+
+print(fibonacci_search(arr, 3))
+# -> None
+```
+
+## API
+
+### fibonacci_search(array, query)
+
+> Return array index if its found, otherwise returns `None`
+
+##### Params:
+
+- `array`: Sorted Array
+- `query`: Element to search for in the array
diff --git a/readme.md b/readme.md
@@ -59,7 +59,9 @@ print(binary_search(arr, 3))
 
 - ### Searches
   - [Binary Search](https://python.allalgorithms.com/searches/binary-search)
+  - [Fibonacci Search](https://python.allalgorithms.com/searches/fibonacci-search)
   - [Jump Search](https://python.allalgorithms.com/searches/jump-search)
+  
 - ### Sorting
   - [Bubble Sort](https://python.allalgorithms.com/sorting/bubble-sort)
   - [Cocktail Shaker Sort](https://python.allalgorithms.com/sorting/cocktail-shaker-sort)
diff --git a/tests/test_searches.py b/tests/test_searches.py
@@ -1,7 +1,10 @@
 import unittest
 
-from allalgorithms.searches import (binary_search, jump_search)
-
+from allalgorithms.searches import (
+    binary_search,
+    fibonacci_search,
+    jump_search
+)
 
 class TestSearches(unittest.TestCase):
 
@@ -12,13 +15,19 @@ def test_binary_search(self):
 		self.assertEqual(None, binary_search(arr, 8))
 		self.assertEqual(None, binary_search(arr, -1))
 
+	def test_fibonacci_search(self):
+		arr = [1, 2, 3, 7, 10, 19, 27, 77]
+		self.assertEqual(3, fibonacci_search(arr, 7))
+		self.assertEqual(7, fibonacci_search(arr, 77))
+		self.assertEqual(None, fibonacci_search(arr, 8))
+		self.assertEqual(None, fibonacci_search(arr, -1))
+    
 	def test_jump_search(self):
 		arr = [1, 2, 3, 7, 10, 19, 27, 77]
 		self.assertEqual(3, binary_search(arr, 7))
 		self.assertEqual(7, binary_search(arr, 77))
 		self.assertEqual(None, binary_search(arr, 8))
 		self.assertEqual(None, binary_search(arr, -1))
 
-
 if __name__ == '__main__':
 	unittest.main()

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,3 @@`
`1`	`1`	`from .binary_search import *`
	`2`	`+from .fibonacci_search import *`
`2`	`3`	`from .jump_search import *`