diff --git a/2022/day6.nim b/2022/day6.nim
index 9a50e95..a23171d 100644
--- a/2022/day6.nim
+++ b/2022/day6.nim
@@ -2,34 +2,38 @@
 import strutils
 let line = strip read_file "input/6"
 
-# proc find_first(n: int): int =
-#     for i in n..line.len:
-#         var s = {line[i-n]}
-#         for c in line[i-n+1..<i]:
-#             s.incl(c)
-#         if s.len == n:
-#             return i
-#     return -1
+proc string_no_duplicate_chars(s: string): bool =
+    # 1M iterations: nim r -d:danger day6.nim  90.29s user 0.27s system 99% cpu 1:30.99 total
+    for i in 0..<s.len:
+        let c = s[i]
+        for j in (i+1)..<s.len:
+            if c == s[j]:
+                return false
+    return true
 
-let a = ord('a')
-proc to_bit(c: char): uint32 =
-    return uint32(1 shl (ord(c) - a))
+proc string_no_duplicate_chars_1iter(s: string): bool =
+    # 1M iterations: nim r -d:danger day6.nim  206.13s user 0.69s system 99% cpu 3:27.83 total
+    for i in 0..<s.len:
+        let c1 = s[i]
+        for c2 in s[i+1..^1]:
+            if c1==c2:
+                return false
+    return true
+
+proc string_no_duplicate_chars_2iter(s: string): bool =
+    # 1M iterations: nim r -d:danger day6.nim  259.15s user 0.76s system 99% cpu 4:20.86 total
+    for i, c1 in s[0..^2]:
+        for c2 in s[i+1..^1]:
+            if c1==c2:
+                return false
+    return true
 
 proc find_first(n: int, skip: int = 0): int =
-    for i in max(n, skip)..line.len:
-        block inner:
-            var s = to_bit line[i-n]
-            for c in line[i-n+1..<i]:
-                let b = to_bit c
-                if (s and b) != 0:
-                    break inner
-                s = s or b
+    for i in max(n, skip)..<line.len:
+        if string_no_duplicate_chars(line[i-n..<i]):
             return i
     return -1
 
-# echo find_first 4
-# echo find_first 14
-
 var four = 0
 var fourteen = 0
 for i in 1..1000000:
diff --git a/2022/day6.scala b/2022/day6.scala
index a254f1f..8ee3629 100644
--- a/2022/day6.scala
+++ b/2022/day6.scala
@@ -2,9 +2,21 @@ import java.nio.file.Files
 import java.nio.file.Paths
 import scala.util.control.NonLocalReturns.*
 
+// scala day6.jar  52.22s user 0.54s system 100% cpu 52.389 total
+extension (s: String) def noDuplicates: Boolean =
+	var i = 0
+	while i < (s.length-1) do
+		val c = s(i)
+		var j = i + 1
+		while j < s.length do
+			if s(j) == c then return false
+			j += 1
+		i += 1
+	return true
+
 def first_unique_run_for(line: String, num: Int, skip: Int = 0): Int = returning {
 	for i <- num.max(skip) until line.length do
-		if line.substring(i-num, i).toCharArray.distinct.size == num then
+		if line.substring(i-num, i).noDuplicates then
 			throwReturn(i)
 	throwReturn(-1)
 }
@@ -20,7 +32,7 @@ def first_unique_run_while(line: String, num: Int, skip: Int = 0): Int =
 @main def main() =
 	val line = Files.readString(Paths.get("input/6")).strip
 	// do_once(line)
-	perf_test(line, 100000)
+	perf_test(line, 1000000)
 
 def do_once(line: String) =
 	val four = first_unique_run_for(line, 4)