3 files changed, 47 insertions(+), 0 deletions(-)

A 4/lex.mll
A 4/t1.ml
A 4/t2.ml

@@ 0,0 1,13 @@
+{
+type token =
+	| Line of (int * int) * (int * int)
+  | Eof
+
+let i = int_of_string
+}
+
+rule token = parse
+	| (['0'-'9']+ as fl)'-'(['0'-'9']+ as fr)','(['0'-'9']+ as sl)'-'(['0'-'9']+ as sr)'\n' {
+    Line ((i fl, i fr), (i sl, i sr))
+  }
+  | eof { Eof }

@@ 0,0 1,18 @@
+open Lex
+
+let rec f lexbuf =
+	match Lex.token lexbuf with
+	| Eof -> []
+	| Line (a, b) -> (a, b) :: f lexbuf
+
+let fully_contains ((l1, r1), (l2, r2)) = l1 <= l2 && r2 <= r1
+
+let both_ways (a, b) = fully_contains (a, b) || fully_contains (b, a)
+
+let () =
+	stdin
+		|> Lexing.from_channel
+		|> f
+		|> List.filter both_ways
+		|> List.length
+		|> Printf.printf "%d\n"

@@ 0,0 1,16 @@
+open Lex
+
+let rec f lexbuf =
+	match Lex.token lexbuf with
+	| Eof -> []
+	| Line (a, b) -> (a, b) :: f lexbuf
+
+let overlaps ((l1, r1), (l2, r2)) = l1 <= l2 && l2 <= r1 || l2 <= l1 && l1 <= r2
+
+let () =
+	stdin
+		|> Lexing.from_channel
+		|> f
+		|> List.filter overlaps
+		|> List.length
+		|> Printf.printf "%d\n"