2022 Day 6 Nim benching

2022/day6.nim

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+{.hint[name]: off.}  # snake_case > camelCase
+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
+
+let a = ord('a')
+proc to_bit(c: char): uint32 =
+    return uint32(1 shl (ord(c) - a))
+
+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
+            return i
+    return -1
+
+# echo find_first 4
+# echo find_first 14
+
+var four = 0
+var fourteen = 0
+for i in 1..1000000:
+    four = find_first 4
+    fourteen = find_first(14, four)
+echo four
+echo fourteen