Merge pull request #48 from sharadbhat/master

Added interpolation search

Author: OmkarPathak

pygorithm/searching/interpolation_search.py

@@ -0,0 +1,65 @@
+"""
+Author: SHARAD BHAT
+Created On: 22nd August 2017
+
+ - Best O(1)
+ - Average O(log(logn))
+ - Worst O(n)
+"""
+
+import inspect
+
+def search(_list, target):
+    """
+    This function performs an interpolation search
+    on a sorted list and returns the index
+    of item if successful else returns False
+
+    :param _list: list to search
+    :param target: item to search for
+    :return: index of item if successful else returns False
+    """
+
+    if type(_list) is not list:
+        raise TypeError("interpolation search only accepts lists, not {}".format(str(type(_list))))
+
+    # First element
+    low = 0
+    # Last element
+    high = len(_list) - 1
+
+    # List is assumed to be sorted
+    while low <= high and target >= _list[low] and target <= _list[high]:
+        position = low + int(((float(high - low) / (_list[high] - _list[low])) * (target - _list[low])))
+
+        if _list[position] == target:
+            return position
+
+        # If target is greater, search in right half
+        if _list[position] < target:
+            low = position + 1
+
+        # If target is smaller, search in left half
+        else:
+            high = position - 1
+
+    return False
+
+
+
+def time_complexities():
+    """
+    Return information on functions
+    time complexity
+    :return: string
+    """
+    return "Best Case: O(1), Average Case: O(log(logn)), Worst Case: O(logn)"
+
+
+def get_code():
+    """
+    easily retrieve the source code
+    of the function
+    :return: source code
+    """
+    return inspect.getsource(search)