diff --git a/coders-strike-back/code6.ml b/coders-strike-back/code6.ml
new file mode 100644
index 0000000..6313b6c
--- /dev/null
+++ b/coders-strike-back/code6.ml
@@ -0,0 +1,217 @@
+
+let open Printf in
+let debug = fprintf stderr in
+
+let checkpoint_ray = 600 in
+
+let module Vector = struct
+  type t = {
+    x : int;
+        y : int
+  }
+
+  let to_string dst : string =
+      (Printf.sprintf "{ x = %d ; y = %d }" dst.x dst.y)
+
+  let create x y = 
+    { x ; y }
+
+  let equal dst src = 
+      (dst.x = src.x) && (dst.y = src.y)
+  
+  let diff dst src =
+    { x = (dst.x - src.x) ;
+          y = (dst.y - src.y)
+    }
+
+  let mult src a =
+    { x = src.x * a ;
+          y = src.y * a 
+    }
+
+  let add dst src = 
+    { x = (src.x + dst.x) ;
+          y = (src.y + dst.y) 
+    }
+
+  let distance (dst:t) (src:t) = 
+    (src.x - dst.x) * (src.x - dst.x) + (src.y - dst.y) * (src.y - dst.y)
+    |> float_of_int
+    |> sqrt
+    |> int_of_float
+
+ let is_touching dst src = 
+    (distance dst src) < (checkpoint_ray / 2)
+    
+  let is_near dst src = 
+    (distance dst src) < (checkpoint_ray * 2)
+
+  let is_far dst src = 
+    ((distance dst src) >= checkpoint_ray * 6)
+end in   
+
+let module Pod = struct
+  type t = {
+    mutable pos : Vector.t ;
+    mutable dir : Vector.t ;
+    }
+    
+  let create () = 
+    { pos = Vector.create 0 0 ;
+      dir = Vector.create 0 0 
+    }  
+end in
+
+let module CheckpointList = struct
+    type t = {
+        mem: Vector.t list ;
+        cur: Vector.t option
+    }
+    
+    let add ck_li elem = 
+        match ck_li.cur with
+        | None -> 
+            { 
+                mem = [] ;
+                cur = Some elem 
+            }
+        | Some cur_elem -> 
+            if (Vector.equal cur_elem elem) then
+                ck_li
+            else
+            { 
+                mem = cur_elem :: ck_li.mem ;
+                cur = Some elem 
+            }
+
+    let create () = 
+        { mem = [] ;
+          cur = None
+        }
+        
+    let inc (ck_li:t) elem = 
+        (ck_li.mem)
+        |> List.map (fun cur -> (Vector.equal elem cur))
+        |> List.fold_left (fun acc elem -> acc || elem) false
+
+end in
+
+let parse_line1 () =
+  let line = input_line stdin in
+  let build_results_fn = (
+    fun x y checkpointx checkpointy checkpointdist checkpointangle -> 
+    (Vector.create x y), 
+    (Vector.create checkpointx checkpointy), 
+    checkpointdist, 
+    checkpointangle
+  ) in
+  Scanf.sscanf line "%d %d %d %d %d %d" build_results_fn
+in
+
+let parse_line2 () =
+  let line = input_line stdin in
+  let build_results_fn = (
+    fun opponentx opponenty -> 
+    (Vector.create opponentx opponenty)
+  ) in
+  Scanf.sscanf line "%d %d" build_results_fn 
+in
+
+let map_center = Vector.create (16000 / 2) (9000 / 2) in 
+let first_turn = ref true in
+let old_pod = ref (Vector.create 0 0) in
+
+let tick = ref 0 in
+let checkpoint_list = ref (CheckpointList.create ()) in
+
+(* laps : le nombre de tours à effectuer pour finir la course. *)
+let parse_init () =
+    let laps =
+        let line = input_line stdin in
+        Scanf.sscanf line "%d" (fun x -> x) 
+    in
+    let checkpoint_count =
+        let line = input_line stdin in
+        Scanf.sscanf line "%d" (fun x -> x)
+    in
+    let parse_checkpoint () = 
+        let line = input_line stdin in
+        Scanf.sscanf line "%d %d" (fun x y -> 
+            Vector.create x y
+        )
+    in
+    for i = 1 to checkpoint_count do
+        let checkpoint = parse_checkpoint () in
+        checkpoint_list := CheckpointList.add !checkpoint_list checkpoint ;
+        ()
+    done
+in
+    
+let pods = Array.create 2 (Pod.create ()) in
+
+(* game loop *)
+while true do
+
+ 
+  (* nextcheckpointdist: distance to the next checkpoint *)
+  (* nextcheckpointangle: angle between your pod orientation and the direction of the next checkpoint *)
+  let pod, checkpoint, checkpoint_dist, checkpoint_angle = parse_line1 () in
+  let opponent = parse_line2 () in 
+
+  if !first_turn then begin
+    old_pod := pod ;
+    first_turn := false
+  end ;
+  let movement = Vector.diff pod !old_pod in
+  
+  if (CheckpointList.inc !checkpoint_list checkpoint) then begin
+      prerr_endline "List already includes this checkpoint" ;
+  end else begin 
+      checkpoint_list := (CheckpointList.add !checkpoint_list checkpoint) ;
+      fprintf stderr "New checkpoint : %s\n%!" (Vector.to_string checkpoint);
+  end ;
+  
+  (* output "x y thrust" : the target position + the power *)
+  let is_aligned = checkpoint_angle > -2 && checkpoint_angle < 2 in
+  let is_near_aligned = 
+      (checkpoint_angle > -15 && checkpoint_angle <= -2) ||
+      (checkpoint_angle >= 2 && checkpoint_angle < 15)
+  in
+  let is_wide_aligned =  
+      (checkpoint_angle > -45 && checkpoint_angle <= -15) ||
+      (checkpoint_angle >= 15 && checkpoint_angle < 45)
+  in
+  let is_aside = 
+      (checkpoint_angle > -85 && checkpoint_angle <= -45) ||
+      (checkpoint_angle >= 45 && checkpoint_angle < 85)
+  in
+  let is_behind = checkpoint_angle >= 85 || checkpoint_angle <= -85 in
+  let use_boost = (!tick > 100) && is_aligned && (Vector.is_far pod checkpoint) in
+
+  debug "angle = %d\n%!" checkpoint_angle ;
+
+  let thrust = 
+    (* droit devant *)
+    if is_behind && (Vector.is_touching pod opponent) then 20
+    else if is_aside && (Vector.is_touching pod opponent) then 20
+    else if is_behind then 6
+    else if is_aside && (Vector.is_near checkpoint pod) then 10
+    else if is_wide_aligned && (Vector.is_near checkpoint pod) then 20
+    else if is_near_aligned && (Vector.is_near checkpoint pod) then 40
+    else 100
+  in
+
+  let power_str = match use_boost with
+      | false -> string_of_int thrust
+      | true -> "BOOST"
+  in
+
+  let target = Vector.add checkpoint (Vector.mult movement (-3)) in
+  
+  printf "%d %d %s\n%!" target.x target.y power_str ;
+
+  tick := !tick + 1 ;
+  old_pod := pod ;
+done;
+
+