2018 Day 5

Author: Programator2

2018/5.txt

@@ -0,0 +1,34 @@
+def polymerize(polymer):
+    l = polymer[:]
+    i = 1
+    changed = False
+    while True:
+        first = l[i - 1]
+        second = l[i]
+        if first == second.swapcase():
+            del l[i - 1]
+            del l[i - 1]
+            changed = True
+        else:
+            i += 1
+        if i >= len(l):
+            # We went through whole string
+            if changed:
+                # If we have changed something, we go over it again
+                changed = False
+                i = 1
+            else:
+                # If nothing changed, the string is finished
+                break
+    return len(l)
+
+
+with open("5.txt") as f:
+    l = f.read()
+    l = tuple(l.rstrip())
+
+polymers = tuple(
+    list(filter(lambda x: x not in c, l)) for c in ("aA", "bB", "cC", "dD")
+)
+
+print(min(map(polymerize, polymers)))

2018/5a.py

@@ -0,0 +1,26 @@
+with open("5.txt") as f:
+    l = f.read()
+    l = list(l.rstrip())
+i = 1
+changed = False
+while True:
+    first = l[i - 1]
+    second = l[i]
+    if first == second.swapcase():
+        del l[i - 1]
+        del l[i - 1]
+        changed = True
+    else:
+        i += 1
+        if i >= len(l):
+            # We went through whole string
+            if changed:
+                # If we have changed something, we go over it again
+                changed = False
+                i = 1
+            else:
+                # If nothing changed, the string is finished
+                break
+
+
+print(len(l))