init commit

1 files changed, 24 insertions, 0 deletions

diff --git a/5/2.py b/5/2.py
new file mode 100644
index 0000000..a172cdd
--- /dev/null
+++ b/5/2.py
@@ -0,0 +1,24 @@
+from collections import defaultdict
+def check(w):
+    pairs = defaultdict(list)
+    rep = False
+    last2 = (None, None)
+    for i, c in enumerate(w):
+        if last2[1] is not None:
+            pairs[(last2[1], c)].append(i)
+        if not rep and last2[0] == c:
+            rep = True
+        last2 = (last2[1], c)
+    if not rep:
+        return False
+    for _, p in pairs.items():
+        if len(p) < 2:
+            continue
+        if len(p) > 2:
+            break
+        if p[1] - p[0] > 1:
+            break
+    else:
+        return False
+    return True
+print(len([w for w in open('input') if check(w)]))