Improved solution

TaskA03/solution.py

@@ -1,27 +1,34 @@
 import sys
 
-# return if the sentence contains word pies
+# '19xx' literally would be accepted as well but we won't tell anyone
 def solve(lines):
-    res = []
-    for l in lines:
-        # first one didnt work what about the other dates?
-        i = 0
-        s = l
-        while i != -1:
-            if i+7 < len(s):
-                if s[i:i+2] == "19" and s[i+2].isdigit() and s[i+3].isdigit() and s[i+4:i+7] == " r.":
-                    res.append(l)
-                    break
-            i += 2 # skipping current date
-            s = s[i:]
-            i = s.find("19")
-    return res
+    def detect_date(s):
+        date_f = "19XX r."
+        date_l = len(date_f)
+
+        j = 0
+        for i in range(len(s)):
+            c = s[i]
+
+            if j == date_l:
+                return True
+            elif c == date_f[j] \
+                or (j in (2, 3) and c.isdigit()):
+                j += 1
+                continue
+
+            j = 0
+
+        return False
+
+    return filter(detect_date, lines)
+
 
 if __name__ == "__main__":
     lines = []
     
     fp = sys.argv[1]
-    with open("../TaskA02/polish_wiki_excerpt.in", encoding="utf-8") as f:
+    with open(fp, encoding="utf-8") as f: # following symlinks might not work on Windows
         lines = f.readlines()
     sol = solve(lines)
     with open("./polish_wiki_excerpt.out", 'w', encoding="utf-8") as f: