2023 - Day 9 part 2

2023/9/9_2.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+# 2023 - Advent Of Code 9 - part 2
+
+# file = 'input_example.txt'
+file = 'input.txt'
+
+
+def all_zeroes(lst):
+    for i in lst:
+        if i != 0:
+            return False
+    return True
+
+
+# pylint: disable=consider-using-with
+input_lines = [line.strip('\n') for line in open(file, encoding="utf-8")]
+res = 0
+
+for line in input_lines:
+    sequence = [int(x) for x in line.split()]
+    print(sequence)
+    diffs_list = [sequence]
+    while not all_zeroes(sequence):
+        diffs = [sequence[s+1] - sequence[s] for s in range(0, len(sequence)-1)]
+        diffs_list.append(diffs)
+        sequence = diffs
+
+    # print(diffs_list)
+
+    for seq in range(len(diffs_list)-1, -1, -1):
+        if seq == len(diffs_list)-1:
+            diffs_list[seq].insert(0, 0)
+        else:
+            d = diffs_list[seq][0] - diffs_list[seq + 1][0]
+            # print(f'{diffs_list[seq][0]} - {diffs_list[seq + 1][0]} = {d}')
+            diffs_list[seq].insert(0, d)
+        # print(f'diffs: {diffs_list[seq]}')
+    res += d
+
+    print()
+
+print(res)