Create Exercise-20-Element-Search.py

Author: swsoyee

Exercise-20-Element-Search.py

@@ -0,0 +1,64 @@
+'''
+Exercise 20: Element Search
+
+Write a function that takes an ordered list of numbers (a list
+where the elements are in order from smallest to largest) and
+another number. The function decides whether or not the given
+number is inside the list and returns (then prints) an
+appropriate boolean.
+
+Extras:
+Use binary search.
+
+'''
+
+# Solution
+def search_in_simple(number_list, query):
+    """
+    Search query in number_list or not.
+    
+    Arguments:
+    number_list -- a list contain all the elements.
+    query -- a element
+    
+    Returns:
+    True/False -- if query in number_list return True, else return False
+    """
+    if query in number_list:
+        return True
+    else:
+        return False
+
+def search_in_binary(number_list, start, end, query):
+    """
+    Search query in number_list or not.
+    
+    Arguments:
+    number_list -- a list contain all the elements.
+    start -- start index.
+    end -- end index.
+    query -- a element.
+    
+    Returns:
+    True/False -- if query in number_list return True, else return False
+    """
+    if start > end:
+        return False
+    mid = int(start + (end - start) / 2)
+    if number_list[mid] > query:
+        return search_in_binary(number_list, start, mid - 1, query)
+    if number_list[mid] < query:
+        return search_in_binary(number_list, mid + 1, end, query)
+    return True
+    
+def main():
+    number_list = [1, 2, 3, 4, 6, 7, 8, 9]
+    query1 = 4
+    query2 = 5
+    print(search_in_simple(number_list, query1))
+    print(search_in_binary(number_list, 0, len(number_list), query1))
+    print(search_in_simple(number_list, query2))
+    print(search_in_binary(number_list, 0, len(number_list), query2))
+    
+if __name__ == "__main__":
+    main()