first commit

02/solve02.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+def read_input():
+    with open('input.txt', 'r') as f:
+        for line in f:
+            yield line.strip()
+
+def compare(a, b):
+    if len(a) != len(b):
+        return None
+
+    change = None
+    for i in range(len(a)):
+        if a[i] != b[i]:
+            if change is None:
+                change = i
+            else:
+                return None
+    return a[:change]+a[change+1:]
+
+boxes = []
+result = None
+for box in read_input():
+    for b in boxes:
+        result = compare(box, b)
+        if result:
+            break
+    if result:
+        break
+    boxes.append(box)
+
+print(result)