How to add the nodes of a tree in a list?
I want to add the nodes of a tree to a list in preorder without concatenating lists.
type 'a bintree = Nil | BT of 'a bintree * 'a * 'a bintree
let preorder t =
let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> addpre left (v :: list)
in addpre t ;;
let ab = BT (BT(Nil, 2, Nil),
7,
BT(BT(Nil, 5, Nil), 6, BT(Nil, 11, Nil)))
let r = preorder ab;;
As you can see I know how to add the nodes from a branch (left or right) but I do not know how to add the nodes from both branches. Can you help me out?
UPDATE
I think I managed to do it
let preorder t = let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> v :: addpre left (addpre right list)
in addpre t ;;
Is it right?
tree ocaml
asked Nov 12 at 9:10
Ghost
1346
add a comment |
I want to add the nodes of a tree to a list in preorder without concatenating lists.
type 'a bintree = Nil | BT of 'a bintree * 'a * 'a bintree
let preorder t =
let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> addpre left (v :: list)
in addpre t ;;
let ab = BT (BT(Nil, 2, Nil),
7,
BT(BT(Nil, 5, Nil), 6, BT(Nil, 11, Nil)))
let r = preorder ab;;
As you can see I know how to add the nodes from a branch (left or right) but I do not know how to add the nodes from both branches. Can you help me out?
UPDATE
I think I managed to do it
let preorder t = let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> v :: addpre left (addpre right list)
in addpre t ;;
Is it right?
tree ocaml
asked Nov 12 at 9:10
Ghost
1346
add a comment |
I want to add the nodes of a tree to a list in preorder without concatenating lists.
type 'a bintree = Nil | BT of 'a bintree * 'a * 'a bintree
let preorder t =
let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> addpre left (v :: list)
in addpre t ;;
let ab = BT (BT(Nil, 2, Nil),
7,
BT(BT(Nil, 5, Nil), 6, BT(Nil, 11, Nil)))
let r = preorder ab;;
As you can see I know how to add the nodes from a branch (left or right) but I do not know how to add the nodes from both branches. Can you help me out?
UPDATE
I think I managed to do it
let preorder t = let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> v :: addpre left (addpre right list)
in addpre t ;;
Is it right?
tree ocaml
asked Nov 12 at 9:10
Ghost
1346
I want to add the nodes of a tree to a list in preorder without concatenating lists.
type 'a bintree = Nil | BT of 'a bintree * 'a * 'a bintree
let preorder t =
let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> addpre left (v :: list)
in addpre t ;;
let ab = BT (BT(Nil, 2, Nil),
7,
BT(BT(Nil, 5, Nil), 6, BT(Nil, 11, Nil)))
let r = preorder ab;;
As you can see I know how to add the nodes from a branch (left or right) but I do not know how to add the nodes from both branches. Can you help me out?
UPDATE
I think I managed to do it
let preorder t = let rec addpre t list =
match t with
| Nil -> list
| BT (left, v, right) -> v :: addpre left (addpre right list)
in addpre t ;;
Is it right?
tree ocaml
tree ocaml
asked Nov 12 at 9:10
Ghost
1346
asked Nov 12 at 9:10
Ghost
1346
edited Nov 12 at 10:56
asked Nov 12 at 9:10
Ghost
1346
asked Nov 12 at 9:10
Ghost
1346
asked Nov 12 at 9:10
Ghost
1346
1346
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You probably want to compute countpree over right after having computed it over left.
A local binding of the computation over the left part could help.
Something like
| BT (left, v, right) ->
let leftpreoder = countpre left (v :: list)
in ...
answered Nov 12 at 9:34
Julien
3527
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using::.
– Julien
Nov 12 at 10:53
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You probably want to compute countpree over right after having computed it over left.
A local binding of the computation over the left part could help.
Something like
| BT (left, v, right) ->
let leftpreoder = countpre left (v :: list)
in ...
answered Nov 12 at 9:34
Julien
3527
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using::.
– Julien
Nov 12 at 10:53
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
add a comment |
You probably want to compute countpree over right after having computed it over left.
A local binding of the computation over the left part could help.
Something like
| BT (left, v, right) ->
let leftpreoder = countpre left (v :: list)
in ...
answered Nov 12 at 9:34
Julien
3527
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using::.
– Julien
Nov 12 at 10:53
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
add a comment |
You probably want to compute countpree over right after having computed it over left.
A local binding of the computation over the left part could help.
Something like
| BT (left, v, right) ->
let leftpreoder = countpre left (v :: list)
in ...
answered Nov 12 at 9:34
Julien
3527
You probably want to compute countpree over right after having computed it over left.
A local binding of the computation over the left part could help.
Something like
| BT (left, v, right) ->
let leftpreoder = countpre left (v :: list)
in ...
answered Nov 12 at 9:34
Julien
3527
answered Nov 12 at 9:34
Julien
3527
answered Nov 12 at 9:34
Julien
3527
answered Nov 12 at 9:34
Julien
3527
3527
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using::.
– Julien
Nov 12 at 10:53
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
add a comment |
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using::.
– Julien
Nov 12 at 10:53
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
I get an error: "Error: This expression has type 'a list but an expression was expected of type 'a The type variable 'a occurs inside 'a list".
– Ghost
Nov 12 at 9:45
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using
::.– Julien
Nov 12 at 10:53
without your code, I can't help you much. My guess is that you are trying to insert the resulting list into a list using
::.– Julien
Nov 12 at 10:53
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
I think I managed to do it. I will update.
– Ghost
Nov 12 at 10:54
add a comment |
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