more cleaning

2023/09/part 1 solution.py

@@ -0,0 +1,50 @@
+with open(r'advent_of_code\2023\09\input.txt', 'r') as file:
+    input = file.readlines()
+
+# print(input)
+
+test_input = '''0 3 6 9 12 15
+1 3 6 10 15 21
+10 13 16 21 30 45'''
+
+
+#input = test_input.split('\n')
+
+def predict_next_number(line):
+    numbers = [int(number) for number in line.split(' ')]
+    differences = [numbers[i+1] - numbers[i] for i in range(len(numbers)-1)]
+    if len(set(differences)) == 1:  # The sequence is simple arithmetic
+        #print('simple')
+        next_number = numbers[-1] + differences[0]
+    else:  # The sequence might be quadratic or more complex rule
+        second_differences = [differences[i+1] - differences[i] for i in range(len(differences)-1)]
+        if len(set(second_differences)) == 1:  # The sequence is quadratic
+            #print('quadratic')
+            next_difference = differences[-1] + second_differences[0]
+            next_number = numbers[-1] + next_difference
+        else: 
+            # The sequence follows a more complex rule
+            # we need to break this down into a series of arithmetic sequences
+            # # Keep finding differences until all differences are 0
+            #print('complex')
+            # Keep finding differences until all differences are 0
+            differences_stack = [differences]
+            while set(differences) != {0}:
+                differences = [differences[i+1] - differences[i] for i in range(len(differences)-1)]
+                differences_stack.append(differences)
+
+            # Now, work our way back up to predict the next number
+            next_number = numbers[-1]
+            for differences in reversed(differences_stack):
+                next_number += differences[-1]  # Add the last difference in the list
+                differences.append(next_number)  # Add the predicted number to the end of the list
+    return next_number
+
+all_predictions = []
+for line in input:
+    prediction = predict_next_number(line)
+    all_predictions.append(prediction)
+    #print(f'line: {line}  ({prediction})')
+
+sum_of_predictions = sum(all_predictions)
+print(f'Sum of predictions: {sum_of_predictions}')

2023/09/part 2 solution.py

@@ -0,0 +1,49 @@
+with open(r'advent_of_code\2023\09\input.txt', 'r') as file:
+    input = file.readlines()
+
+# print(input)
+
+test_input = '''0 3 6 9 12 15
+1 3 6 10 15 21
+10 13 16 21 30 45'''
+
+#input = test_input.split('\n')
+
+def predict_next_number(line, is_reversed=True):
+    numbers = [int(number) for number in line.split(' ')]
+    if is_reversed == True:
+        numbers.reverse()  # Reverse the list of numbers
+    differences = [numbers[i+1] - numbers[i] for i in range(len(numbers)-1)]
+    if len(set(differences)) == 1:  
+    # The sequence is simple arithmetic
+        previous_number = numbers[-1] + differences[0]
+    else:
+    # The sequence might be quadratic or more complex rule
+        second_differences = [differences[i+1] - differences[i] for i in range(len(differences)-1)]
+        if len(set(second_differences)) == 1:  # The sequence is quadratic
+            previous_difference = differences[-1] + second_differences[0]
+            previous_number = numbers[-1] + previous_difference
+        else: 
+    # The sequence follows a more complex rule
+            differences_stack = [differences]
+            while not all(difference == 0 for difference in differences):
+                differences = [differences[i+1] - differences[i] for i in range(len(differences)-1)]
+                differences_stack.append(differences)
+
+            # Now, work our way back up to predict the previous number
+            previous_number = numbers[-1]
+            for differences in reversed(differences_stack):
+                previous_number += differences[-1]  # Add the last difference in the list
+                differences.append(previous_number)  # Add the predicted number to the end of the list
+    return previous_number
+
+all_predictions = []
+for line in input:
+    prediction = predict_next_number(line)
+    all_predictions.append(prediction)
+
+total = 0
+for prediction in all_predictions:
+    total += prediction
+
+print(f'Sum of predictions: {total}')