Fix old exercises

Author: Shehab Abdel-Salam

chapters/chapter02_variables/exercises/exercise_07.py

@@ -1,13 +1,19 @@
-# Exercise 07 - May The Force Be With You
-# Write a program that calculates the force of gravity between two objects.
-# The formula to calculate the force of gravity is:
-# F = G * (m1 * m2) / r^2
-# https://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation
+# Exercise 07 - Midpoint Calculation
+# Write a program that calculates the midpoint between two points.
+# The program should take the x and y coordinates of two points as input
+# and return the midpoint as a tuple.
 
-G = 6.674 * 10**-11  # Gravitational constant
+# The formula for calculating the midpoint is as follows:
+# midpoint_x = (x1 + x2) / 2
+# midpoint_y = (y1 + y2) / 2
+# The midpoint is the point that is exactly halfway between two points.
+# For example, given the points (1, 2) and (3, 4), the midpoint should be (2, 3).
 
 
-def calculate_gravity_force(mass1, mass2, distance):
+# Note: you can return more than one value by separating them with a comma.
+
+
+def calculate_midpoint(x1, y1, x2, y2):
     # Your code should go here.
 
     return ...

chapters/chapter02_variables/tests/test_ch02.py

@@ -4,7 +4,7 @@
 from ..exercises.exercise_04 import compute_length_difference
 from ..exercises.exercise_05 import compute_average_grade
 from ..exercises.exercise_06 import convert_binary_to_decimal
-from ..exercises.exercise_07 import calculate_gravity_force
+from ..exercises.exercise_07 import calculate_midpoint
 
 
 def test_e01():
@@ -49,7 +49,7 @@ def test_e06():
 
 
 def test_e07():
-    assert calculate_gravity_force(1, 1) == 9.8
-    assert calculate_gravity_force(5, 2) == 19.6
-    assert calculate_gravity_force(10, 5) == 49
-    assert calculate_gravity_force(100, 10) == 980
+    assert calculate_midpoint(0, 0, 0, 0) == (0.0, 0.0)
+    assert calculate_midpoint(1, 2, 3, 4) == (2.0, 3.0)
+    assert calculate_midpoint(5, 10, 15, 20) == (10.0, 15.0)
+    assert calculate_midpoint(-5, -10, -15, -20) == (-10.0, -15.0)

chapters/chapter03_operators/exercises/exercise_13.py

@@ -1,15 +1,16 @@
-# Exercise 13 - ISBN Verifier
-# Write a program that checks if a given ISBN number is valid.
-# The ISBN is valid if:
-# - It consists of 10 digits.
-# - The first 9 digits are numbers.
-# - The last digit is a number or an uppercase X.
-# - The ISBN is valid if the sum of the 10 digits multiplied by their position modulo 11 is 0.
-# The program should return True if the ISBN is valid and False otherwise.
-# formula: (d1*1 + d2*2 + d3*3 + d4*4 + d5*5 + d6*6 + d7*7 + d8*8 + d9*9 + d10*10) % 11 == 0
+# Exercise 13 - Add Without Plus Operator
+# This program below adds two numbers without using the '+' operator.
 
+# There is a bug in the code below. Find it and fix it.
 
-def is_valid_isbn(isbn):
-    # Your code should go here.
 
-    return ...
+def add_without_plus_operator(a, b):
+    # Continue the loop until the carry (b) becomes zero.
+    while b != 0:
+        # Calculate the bitwise AND of 'a' and 'b'.
+        data = a & b
+        # XOR 'a' and 'b' to get the sum without considering carry.
+        a = a ^ b
+        b = data >> 1
+
+    return a

chapters/chapter03_operators/tests/test_ch03.py

@@ -3,7 +3,7 @@
 from ..exercises.exercise_10 import bitwise_operations
 from ..exercises.exercise_11 import area_of_triangle
 from ..exercises.exercise_12 import calculate_hypotenuse
-from ..exercises.exercise_13 import is_valid_isbn
+from ..exercises.exercise_13 import add_without_plus_operator
 from ..exercises.exercise_14 import generate_stats_report
 
 
@@ -41,12 +41,11 @@ def test_e12():
 
 
 def test_e13():
-    assert is_valid_isbn("123456789X") is True
-    assert is_valid_isbn("987654321X") is True
-    assert is_valid_isbn("1234567890") is False
-    assert is_valid_isbn("1234567891") is False
-    assert is_valid_isbn("1234567892") is False
-    assert is_valid_isbn("1234567893") is False
+    assert add_without_plus_operator(0, 0) == 0
+    assert add_without_plus_operator(10, 2) == 12
+    assert add_without_plus_operator(2, 10) == 12
+    assert add_without_plus_operator(-20, 10) == -10
+    assert add_without_plus_operator(-10, -20) == -30
 
 
 def test_e14():

chapters/chapter08_files/exercises/exercise_60.py

@@ -13,6 +13,11 @@
 
 
 def course_grades_summary(file_name: str) -> list[tuple[str, float]]:
-    # Your code should go here.
-
-    ...
+    with open(file_name) as file:
+        summary = []
+        for line in file:
+            course, *grades = line.strip().split(":")
+            grades = [int(grade) for grade in grades[0].split(",")]
+            average = sum(grades) / len(grades)
+            summary.append((course, average))
+    return summary

chapters/chapter08_files/exercises/exercise_61.py

@@ -1,34 +1,57 @@
 # Exercise 61 - Inventory Management System
-# Write a CSV file containing inventory data and generates a report on stock levels and restock alerts.
-# The CSV file contains columns: item_name, item_id, quantity, and price.
-# Read the CSV file and calculate the total value of the inventory.
+# Given a text file containing inventory data and generates a report on stock levels and restock alerts.
+# This file contains columns: item_name, quantity, and price.
+# Read the file and calculate the total value of the inventory.
 # Identify items with stock levels below the restock threshold and store them in a list.
 # Return a dictionary containing the total inventory value and the list of items that need restocking.
 
-# Example data.csv:
-# item_name,item_id,quantity,price
+# Example data.txt:
+# item_name,quantity,price
 # Apple,1,100,0.5
 # Banana,2,200,0.3
 # Orange,3,150,0.4
 
-# The function should return:
-
+# With restock threshold of 200. The function should return:
 # {
-#     "total_inventory_value": 140.0,
-#     "restock_alerts": [
-#         {"item_name": "Apple", "item_id": 1, "quantity": 100, "price": 0.5},
-#         {"item_name": "Orange", "item_id": 3, "quantity": 150, "price": 0.4},
-#     ],
+#     "total_inventory_value": 170.0,
+#     "restock_alerts": ["Apple", "Orange"]
 # }
 
-# The restock threshold is 200 items.
 # The total inventory value is calculated as the sum of quantity * price for each item.
 # The restock alerts are items with a quantity below the restock threshold.
 
 
 def inventory_management(
     file_name: str, restock_threshold: int
 ) -> dict[str, list[dict[str, str]]]:
-    # Your code should go here.
+    total_inventory_value = 0.0
+    restock_alerts = []
+
+    with open(file_name, "r") as file:
+        # Read the header line
+        header = file.readline().strip().split(",")
+
+        # Check if header is correct
+        if header != ["item_name", "quantity", "price"]:
+            raise ValueError("Incorrect CSV format")
+
+        for line in file:
+            # Split each line into columns
+            columns = line.strip().split(",")
+
+            # Extract data from columns
+            item_name = columns[0]
+            quantity = int(columns[1])
+            price = float(columns[2])
+
+            # Calculate the total inventory value
+            total_inventory_value += quantity * price
+
+            # Check if restock is needed
+            if quantity < restock_threshold:
+                restock_alerts.append(item_name)
 
-    ...
+    return {
+        "total_inventory_value": total_inventory_value,
+        "restock_alerts": restock_alerts,
+    }

chapters/chapter08_files/exercises/exercise_62.py

@@ -17,6 +17,10 @@
 
 
 def is_file_sorted(file_name: str) -> bool:
-    # Your code should go here.
-
-    ...
+    numbers = []
+    with open(file_name) as file:
+        for line in file:
+            if not line.strip().isdigit():
+                continue
+            numbers.append(int(line))
+    return numbers == sorted(numbers)