change prototype of binary_recursive function including parameters for low and high index

Author: MMachmerth

run_back/checks/__init__.py

@@ -29,7 +29,8 @@ def has_function():
 def test_sample_1():
     """sample test: finds 8 in list"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([6, 7, 8, 9, 10], 8)
+    list = [6, 7, 8, 9, 10]
+    result = module.binary_recursive(list, 8, 0, len(list) - 1)
     if result != 2:
         raise check50.Mismatch(2, result)
 
@@ -38,7 +39,8 @@ def test_sample_1():
 def test_sample_2():
     """sample test: finds 17 in list"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([11, 13, 15, 17, 18], 17)
+    list = [11, 13, 15, 17, 18]
+    result = module.binary_recursive(list, 17, 0, len(list) - 1)
     if result != 3:
         raise check50.Mismatch(3, result)
 
@@ -47,7 +49,8 @@ def test_sample_2():
 def test_sample_3():
     """sample test: returns -1 for missing element"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([3, 4, 5, 6, 7], 1)
+    list = [3, 4, 5, 6, 7]
+    result = module.binary_recursive(list, 1, 0, len(list) - 1)
     if result != -1:
         raise check50.Mismatch(-1, result)
 
@@ -56,7 +59,8 @@ def test_sample_3():
 def test_sample_4():
     """sample test: empty list returns -1"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([], 13)
+    list = []
+    result = module.binary_recursive(list, 13, 0, len(list) - 1)
     if result != -1:
         raise check50.Mismatch(-1, result)
 
@@ -65,7 +69,8 @@ def test_sample_4():
 def test_first():
     """finds first element"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([1, 2, 3], 1)
+    list = [1, 2, 3]
+    result = module.binary_recursive(list, 1, 0, len(list) - 1)
     if result != 0:
         raise check50.Mismatch(0, result)
 
@@ -74,7 +79,8 @@ def test_first():
 def test_last():
     """finds last element"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([10, 20, 30, 40, 50], 50)
+    list = [10, 20, 30, 40, 50]
+    result = module.binary_recursive(list, 50, 0, len(list) - 1)
     if result != 4:
         raise check50.Mismatch(4, result)
 
@@ -84,7 +90,7 @@ def test_duplicates():
     """handles duplicates correctly (returns any valid index)"""
     module = check50.py.import_(FILE_NAME)
     lst = [1, 2, 2, 2, 3, 4]
-    result = module.binary_recursive(lst, 2)
+    result = module.binary_recursive(lst, 2, 0, len(lst) - 1)
     if result not in (1, 2, 3):
         msg = f"Expected index 1, 2 or 3 but got {result}"
         raise check50.Failure(msg)
@@ -94,7 +100,8 @@ def test_duplicates():
 def test_negative_numbers():
     """works with negative numbers"""
     module = check50.py.import_(FILE_NAME)
-    result = module.binary_recursive([-10, -5, 0, 5, 10], -5)
+    list = [-10, -5, 0, 5, 10]
+    result = module.binary_recursive(list, -5, 0, len(list) - 1)
     if result != 1:
         raise check50.Mismatch(1, result)
 
@@ -109,7 +116,7 @@ def test_random():
     lst = sorted(random.sample(range(0, 500), 30))
     key = random.choice(lst)
     expected = lst.index(key)
-    result = module.binary_recursive(lst, key)
+    result = module.binary_recursive(lst, key, 0, len(lst) - 1)
 
     if result != expected:
         raise check50.Mismatch(expected, result)
@@ -131,7 +138,7 @@ def __getitem__(self, index):
     lst = WatchList(range(100_000))
     lst.accesses = 0
 
-    module.binary_recursive(lst, 99999)
+    module.binary_recursive(lst, 99999, 0, len(lst) - 1)
 
     if lst.accesses > 1000:
         msg = "Too many list accesses; algorithm may not be binary search"
@@ -155,7 +162,8 @@ def wrapper(*args, **kwargs):
     module.binary_recursive = wrapper
 
     # Perform a search that requires recursion
-    result = module.binary_recursive([1, 2, 3, 4, 5, 6, 7], 6)
+    list = [1, 2, 3, 4, 5, 6, 7]
+    result = module.binary_recursive(list, 6, 0, len(list) - 1)
 
     # Restore original function (cleanliness, not required but good practice)
     module.binary_recursive = original

run_back/checks/main.py

@@ -8,9 +8,25 @@
 
 <p>
   {% include "file.html" %}
-  Implementieren Sie die folgende Funktion in Ihrer Datei:
+  Implementieren Sie die folgende Funktion in Ihrer Datei. Die Überpüfung der Array Grenzen
+  ist bereits erfolgt, vervollständigen Sie den Code für die rekursive Suche:
   <code>
-    def binary_recursive(lst, key):
+    def binary_recursive(lst, key, low, high):
+
+        if len(lst) == 0:
+            # List is empty no search needed
+            return -1
+
+        if low > len(lst)-1:
+            if low != 0:
+                print("Index out of range: low ", low)
+            return -1
+
+        if high > len(lst)-1:
+            print("Index out of range: high ", high)
+            return -1
+
+        # TODO Implementieren Sie hier die rekursive binäre Suche 
   </code>
 </p>
 
@@ -57,10 +73,21 @@
   <li>
     Testen Sie die Funktion zum Beispiel mit:
     <pre><code>
-print(binary_recursive([6, 7, 8, 9, 10], 8))        # Erwartet: 2
-print(binary_recursive([11, 13, 15, 17, 18], 17))   # Erwartet: 3
-print(binary_recursive([3, 4, 5, 6, 7], 1))         # Erwartet: -1
-print(binary_recursive([], 13))                     # Erwartet: -1
+list = [6, 7, 8, 9, 10]
+high_idx = len(list) - 1
+print(binary_recursive(list, 8, low = 0, high = high_idx))   # Erwartet: 2
+
+list = [11, 13, 15, 17, 18]
+high_idx = len(list) - 1
+print(binary_recursive(list, 17, low = 0, high = high_idx))  # Erwartet: 3
+
+list = [3, 4, 5, 6, 7]
+high_idx = len(list) - 1
+print(binary_recursive(list, 1, low = 0, high = high_idx))   # Erwartet: -1
+
+list = []
+high_idx = len(list) - 1
+print(binary_recursive(list, 13, low = 0, high = high_idx))  # Erwartet: -1
     </code></pre>
   </li>
 </ul>