In Circle?

• Write a function in_circle that checks if a point $(x,y)$ is inside the circle centered at the origin and of radius $r$.

• In a mathematical expression,

$$ x^2 + y^2 \le r^2 $$

• Boilerplate source files {go,jl,ml,rs}/in_circle.{go,jl,ml,rs} containing the test code is generated and shown below.

• Edit the source files either by opening them in a text editor (e.g., vscode), or editing the cells below and executing them.

1. AI tutor

1-1. Prepare

• Your personal AI tutor is provided for questions and feedback
• Execute the following cell before you use it

import heytutor

1-2. Examples

1-2-1. A general question

%%hey
How to write a function in Go?

1-2-2. A hint on this specific problem

%%hey
Give me a hint on this problem for Rust

1-2-3. NEW: A few builtin variables

• {file:FILENAME} is the content of FILE
• {bash[-1]} is the output of the last %%bash_ cell, {bash[-2]} that of the second last %%bash_ cell, etc.
• {problem} is the content of the file you specified by %%hey problem_file=foo.md
• {answer} is the content of the file you specified by %%hey answer_file=go/foo.go

1-2-4. Help when you struggle

%%hey answer_file=go/foo.go
I get this error when I compile it. What's wrong?"

My program:
{answer}

Error message:
{bash[-1]}

1-2-5. Ask feedback

• You are encouraged to ask a feedback once you think you are done with the problem, to know if there is a better answer. You can do so by something like:

%%hey problem_file=foo.md answer_file=go/foo.md
Give me a feedback to my answer.

Problem:
{problem}

My Answer:
{answer}

2. Go

2-1. Baseline code

import heytutor

%%writefile_ go/in_circle.go
package main
import "fmt"

/** begin my answer */

func inCircle(x,y,r float64) bool {
    return x*x + y*y <= r*r
}
/** end my answer */
func main() {
	if !inCircle(1, 1, 2) { panic("wrong") }
	if !inCircle(3, 4, 6) { panic("wrong") }
	if  inCircle(3, 0, 2) { panic("wrong") }
	fmt.Println("OK")
}

2-2. Compile

%%bash_
export PATH=${PATH}:~/.local/go/bin:~/go/bin
go build -o go/in_circle go/in_circle.go

• Note: when you run go or other Go commands in a terminal (SSH or Jupyter terminal), you need to execute the first line (export PATH=${PATH}:~/go/bin)
• You may consider adding that line in your ~/.bash_profile

2-3. Run

%%bash_
go/in_circle

2-4. Ask Questions or Get Feedback

%%hey problem_file=in_circle.md answer_file=go/in_circle.go

Problem:
{problem}
My Answer (between /** begin my answer */ and /** end my answer */):
{answer}

Give me a feedback to my answer.

3. Julia

3-1. Baseline code

import heytutor

%%writefile_ jl/in_circle.jl
### begin my answer

in_circle(x,y,r) = x*x + y*y <= r*r
### end my answer

function main()
    @assert  in_circle(1, 1, 2)
    @assert  in_circle(3, 4, 6)
    @assert !in_circle(3, 0, 2)
    println("OK")
end

main()

3-2. Compile

• Julia code is compiled "just in time" (compiled upon executed), so does not need a specific action for compilation before you run

3-3. Run

%%bash_
export PATH=${PATH}:~/.juliaup/bin
julia jl/in_circle.jl

• Note: when you run julia or other Julia commands in a terminal (SSH or Jupyter terminal), you need to execute the first line (export PATH=${PATH}:~/.juliaup/bin)
• You may consider adding that line in your ~/.bash_profile

3-4. Interactive execution

• julia command also serves is an interactive command for Julia programs

• You can run a source code and continue interaction

$ julia -i jl/in_circle.jl

• For trial and error, you may also consider creating a Julia notebook

3-5. Ask Questions or Get Feedback

%%hey problem_file=in_circle.md answer_file=jl/in_circle.jl

Problem:
{problem}

My Answer (between ### begin my answer and ### end my answer):
{answer}

Give me a feedback to my answer.

4. OCaml

4-1. Baseline code

import heytutor

%%writefile_ ml/in_circle.ml
(** begin my answer *)

let in_circle x y r = x *. x +. y *. y <= r *. r;;
(** end my answer *)

let main () =
  assert (in_circle 1.0 1.0 2.0);
  assert (in_circle 3.0 4.0 6.0);
  assert (not (in_circle 3.0 0.0 2.0));
  Printf.printf "OK\n"
;;

main()

4-2. Compile

%%bash_
eval $(opam env)
ocamlc ml/in_circle.ml -o ml/in_circle

• Note: when you run ocamlc or other OCaml commands (see below) in a terminal (SSH or Jupyter terminal), you need to execute the first line (eval $(opam env))
• You may consider adding that line in your ~/.bash_profile

4-3. Run

%%bash_
ml/in_circle

4-4. Interactive execution

• ocaml command is an interactive command for OCaml programs

• In terminal (Jupyter or SSH), you can directly run a source code

$ eval $(opam env)   # once in your session or put it in ~/.bash_profile
$ ocaml ml/in_circle.ml

• You can run a source code and continue interaction

$ eval $(opam env)   # once in your session or put it in ~/.bash_profile
$ ocaml -init ml/in_circle.ml

• For trial and error, you may also consider creating an OCaml notebook

4-5. Ask Questions or Get Feedback

%%hey problem_file=in_circle.md answer_file=ml/in_circle.ml

Problem:
{problem}

My Answer (between (** begin my answer *) and (** end my answer *)):
{answer}

Give me a feedback to my answer.

5. Rust

5-1. Baseline code

import heytutor

%%writefile_ rs/in_circle.rs
/** begin my answer */

fn in_circle(x: f64, y: f64, r: f64) -> bool {
    x*x + y*y <= r*r
}
/** end my answer */

fn main() {
    assert!( in_circle(1.0, 1.0, 2.0));
    assert!( in_circle(3.0, 4.0, 6.0));
    assert!(!in_circle(3.0, 0.0, 2.0));
    println!("OK")
}

5-2. Compile

%%bash_
. ~/.cargo/env
rustc rs/in_circle.rs -o rs/in_circle

• Note: when you run rustc or other Rust commands in a terminal (SSH or Jupyter terminal), you need to execute the first line (. ~/.cargo/env)
• You may consider adding that line in your ~/.bash_profile

5-3. Run

%%bash_
rs/in_circle

5-4. Ask Questions or Get Feedback

%%hey problem_file=in_circle.md answer_file=rs/in_circle.rs

Problem:
{problem}

My Answer (between /** begin my answer */ and /** end my answer */):
{answer}

Give me a feedback to my answer.