Simple Arithmetic Function (1)

• Write a function f in one of the four languages, that takes three floating point numbers $a$, $b$, and $c$ and return $a^2 + b^2 - c^2$.

• In a mathematical expression,

$$ f(a, b, c) = a^2 + b^2 - c^2 $$

• Use 64 bit floating point numbers both for inputs and the output.

• Boilerplate source files {go,jl,ml,rs}/a2b2c2.{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/a2b2c2.go
package main
import "fmt"
import "math"

/** begin my answer */

func f(a, b, c float64) float64 {
	return a * a + b * b - c * c
}
/** end my answer */
func main() {
	if !(math.Abs(f(1.0, 2.0, 3.0) - -4.0) < 1.0e-5) { panic("wrong") }
	if !(math.Abs(f(3.0, 4.0, 5.0) -  0.0) < 1.0e-5) { panic("wrong") }
	if !(math.Abs(f(5.0, 6.0, 7.0) - 12.0) < 1.0e-5) { panic("wrong") }
	fmt.Println("OK")
}

2-2. Compile

%%bash_
export PATH=${PATH}:~/.local/go/bin:~/go/bin
go build -o go/a2b2c2 go/a2b2c2.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/a2b2c2

2-4. Ask Questions or Get Feedback

%%hey problem_file=a2b2c2.md answer_file=go/a2b2c2.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/a2b2c2.jl
### begin my answer

function f(a, b, c)
    a * a + b * b - c * c
end
### end my answer

function main()
    @assert abs(f(1.0, 2.0, 3.0) - -4.0) <= 1.0e-5
    @assert abs(f(3.0, 4.0, 5.0) -  0.0) <= 1.0e-5
    @assert abs(f(5.0, 6.0, 7.0) - 12.0) <= 1.0e-5
    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/a2b2c2.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/a2b2c2.jl

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

3-5. Ask Questions or Get Feedback

%%hey problem_file=a2b2c2.md answer_file=jl/a2b2c2.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/a2b2c2.ml
(** begin my answer *)

let f a b c = a *. a +. b *. b -. c *. c;;
(** end my answer *)

let main () =
  assert (abs_float (f 1.0 2.0 3.0 -. -4.0) < 1.0e-5);
  assert (abs_float (f 3.0 4.0 5.0 -.  0.0) < 1.0e-5);
  assert (abs_float (f 5.0 6.0 7.0 -. 12.0) < 1.0e-5);
  Printf.printf "OK\n"
;;

main()

4-2. Compile

%%bash_
eval $(opam env)
ocamlc ml/a2b2c2.ml -o ml/a2b2c2

• 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/a2b2c2

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/a2b2c2.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/a2b2c2.ml

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

4-5. Ask Questions or Get Feedback

%%hey problem_file=a2b2c2.md answer_file=ml/a2b2c2.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/a2b2c2.rs
/** begin my answer */

fn f(a : f64, b : f64, c : f64) -> f64 {
    a * a + b * b - c * c
}
/** end my answer */

fn main() {
    assert!((f(1.0, 2.0, 3.0) - -4.0).abs() < 1.0e-5);
    assert!((f(3.0, 4.0, 5.0) - -0.0).abs() < 1.0e-5);
    assert!((f(5.0, 6.0, 7.0) - 12.0).abs() < 1.0e-5);
    println!("OK")
}

5-2. Compile

%%bash_
. ~/.cargo/env
rustc rs/a2b2c2.rs -o rs/a2b2c2

• 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/a2b2c2

5-4. Ask Questions or Get Feedback

%%hey problem_file=a2b2c2.md answer_file=rs/a2b2c2.rs

Problem:
{problem}

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

Give me a feedback to my answer.