From 218864164929b83b3eaca48fe5aa3b7768230c91 Mon Sep 17 00:00:00 2001
From: Vahor <nathan.d0601@gmail.com>
Date: Fri, 30 Jun 2023 18:59:05 +0200
Subject: [PATCH] init

---
 .cargo/config           |    2 +
 .gitignore              |    2 +
 Cargo.lock              | 2011 +++++++++++++++++++++++++++++++++++++++
 Cargo.toml              |   19 +
 README.md               |    0
 src/fetcher.rs          |  217 +++++
 src/lib.rs              |    5 +
 src/main.rs             |  362 +++++++
 src/problem/mod.rs      |    0
 src/solution/mod.rs     |  237 +++++
 src/util/linked_list.rs |   29 +
 src/util/mod.rs         |    8 +
 src/util/point.rs       |   23 +
 src/util/testing.rs     |    1 +
 src/util/tree.rs        |   57 ++
 src/util/vec_string.rs  |    5 +
 template.rs             |   24 +
 17 files changed, 3002 insertions(+)
 create mode 100644 .cargo/config
 create mode 100644 .gitignore
 create mode 100644 Cargo.lock
 create mode 100644 Cargo.toml
 create mode 100644 README.md
 create mode 100644 src/fetcher.rs
 create mode 100644 src/lib.rs
 create mode 100644 src/main.rs
 create mode 100644 src/problem/mod.rs
 create mode 100644 src/solution/mod.rs
 create mode 100644 src/util/linked_list.rs
 create mode 100644 src/util/mod.rs
 create mode 100644 src/util/point.rs
 create mode 100644 src/util/testing.rs
 create mode 100644 src/util/tree.rs
 create mode 100644 src/util/vec_string.rs
 create mode 100644 template.rs

diff --git a/.cargo/config b/.cargo/config
new file mode 100644
index 00000000..b05dfbcf
--- /dev/null
+++ b/.cargo/config
@@ -0,0 +1,2 @@
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diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..96ef862d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+target/
+.idea/
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 00000000..a8df0eae
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,2011 @@
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+ "wasm-bindgen-backend",
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+ "winapi-x86_64-pc-windows-gnu",
+]
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+dependencies = [
+ "winapi 0.3.8",
+]
+
+[[package]]
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+ "winapi 0.2.8",
+ "winapi-build",
+]
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 00000000..9fdbe995
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+name = "leetcode-rust"
+version = "0.1.0"
+authors = ["alei <rayingecho@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+reqwest = "0.9.8"
+serde = "1.0"
+serde_json = "1.0"
+serde_derive = "1.0"
+rand = "0.6.5"
+regex = "1.3.4"
+futures = { version = "0.3.3", features = ["thread-pool"] }
+surf = "1.0.3"
+
+[lib]
+doctest = false
+test = true
diff --git a/README.md b/README.md
new file mode 100644
index 00000000..e69de29b
diff --git a/src/fetcher.rs b/src/fetcher.rs
new file mode 100644
index 00000000..c356dee8
--- /dev/null
+++ b/src/fetcher.rs
@@ -0,0 +1,217 @@
+extern crate reqwest;
+extern crate serde_json;
+
+use serde_json::Value;
+use std::fmt::{Display, Error, Formatter};
+
+const PROBLEMS_URL: &str = "https://leetcode.com/api/problems/algorithms/";
+const GRAPHQL_URL: &str = "https://leetcode.com/graphql";
+const QUESTION_QUERY_STRING: &str = r#"
+query questionData($titleSlug: String!) {
+    question(titleSlug: $titleSlug) {
+        content
+        stats
+        codeDefinition
+        sampleTestCase
+        metaData
+    }
+}"#;
+const QUESTION_QUERY_OPERATION: &str = "questionData";
+
+pub fn get_problem(frontend_question_id: u32) -> Option<Problem> {
+    let problems = get_problems().unwrap();
+    for problem in problems.stat_status_pairs.iter() {
+        if problem.stat.frontend_question_id == frontend_question_id {
+            if problem.paid_only {
+                return None;
+            }
+
+            let client = reqwest::Client::new();
+            let resp: RawProblem = client
+                .post(GRAPHQL_URL)
+                .json(&Query::question_query(
+                    problem.stat.question_title_slug.as_ref().unwrap(),
+                ))
+                .send()
+                .unwrap()
+                .json()
+                .unwrap();
+            return Some(Problem {
+                title: problem.stat.question_title.clone().unwrap(),
+                title_slug: problem.stat.question_title_slug.clone().unwrap(),
+                code_definition: serde_json::from_str(&resp.data.question.code_definition).unwrap(),
+                content: resp.data.question.content,
+                sample_test_case: resp.data.question.sample_test_case,
+                difficulty: problem.difficulty.to_string(),
+                question_id: problem.stat.frontend_question_id,
+                return_type: {
+                    let v: Value = serde_json::from_str(&resp.data.question.meta_data).unwrap();
+                    v["return"]["type"].to_string().replace("\"", "")
+                },
+            });
+        }
+    }
+    None
+}
+
+pub async fn get_problem_async(problem_stat: StatWithStatus) -> Option<Problem> {
+    if problem_stat.paid_only {
+        println!(
+            "Problem {} is paid-only",
+            &problem_stat.stat.frontend_question_id
+        );
+        return None;
+    }
+    let resp = surf::post(GRAPHQL_URL).body_json(&Query::question_query(
+        problem_stat.stat.question_title_slug.as_ref().unwrap(),
+    ));
+    if resp.is_err() {
+        println!(
+            "Problem {} not initialized due to some error",
+            &problem_stat.stat.frontend_question_id
+        );
+        return None;
+    }
+    let resp = resp.unwrap().recv_json().await;
+    if resp.is_err() {
+        println!(
+            "Problem {} not initialized due to some error",
+            &problem_stat.stat.frontend_question_id
+        );
+        return None;
+    }
+    let resp: RawProblem = resp.unwrap();
+    return Some(Problem {
+        title: problem_stat.stat.question_title.clone().unwrap(),
+        title_slug: problem_stat.stat.question_title_slug.clone().unwrap(),
+        code_definition: serde_json::from_str(&resp.data.question.code_definition).unwrap(),
+        content: resp.data.question.content,
+        sample_test_case: resp.data.question.sample_test_case,
+        difficulty: problem_stat.difficulty.to_string(),
+        question_id: problem_stat.stat.frontend_question_id,
+        return_type: {
+            let v: Value = serde_json::from_str(&resp.data.question.meta_data).unwrap();
+            v["return"]["type"].to_string().replace("\"", "")
+        },
+    });
+}
+
+pub fn get_problems() -> Option<Problems> {
+    reqwest::get(PROBLEMS_URL).unwrap().json().unwrap()
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Problem {
+    pub title: String,
+    pub title_slug: String,
+    pub content: String,
+    #[serde(rename = "codeDefinition")]
+    pub code_definition: Vec<CodeDefinition>,
+    #[serde(rename = "sampleTestCase")]
+    pub sample_test_case: String,
+    pub difficulty: String,
+    pub question_id: u32,
+    pub return_type: String,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct CodeDefinition {
+    pub value: String,
+    pub text: String,
+    #[serde(rename = "defaultCode")]
+    pub default_code: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Query {
+    #[serde(rename = "operationName")]
+    operation_name: String,
+    variables: serde_json::Value,
+    query: String,
+}
+
+impl Query {
+    fn question_query(title_slug: &str) -> Query {
+        Query {
+            operation_name: QUESTION_QUERY_OPERATION.to_owned(),
+            variables: json!({ "titleSlug": title_slug }),
+            query: QUESTION_QUERY_STRING.to_owned(),
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct RawProblem {
+    data: Data,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Data {
+    question: Question,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Question {
+    content: String,
+    stats: String,
+    #[serde(rename = "codeDefinition")]
+    code_definition: String,
+    #[serde(rename = "sampleTestCase")]
+    sample_test_case: String,
+    #[serde(rename = "metaData")]
+    meta_data: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Problems {
+    user_name: String,
+    num_solved: u32,
+    num_total: u32,
+    ac_easy: u32,
+    ac_medium: u32,
+    ac_hard: u32,
+    pub stat_status_pairs: Vec<StatWithStatus>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct StatWithStatus {
+    pub stat: Stat,
+    difficulty: Difficulty,
+    paid_only: bool,
+    is_favor: bool,
+    frequency: u32,
+    progress: u32,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Stat {
+    question_id: u32,
+    #[serde(rename = "question__article__slug")]
+    question_article_slug: Option<String>,
+    #[serde(rename = "question__title")]
+    question_title: Option<String>,
+    #[serde(rename = "question__title_slug")]
+    question_title_slug: Option<String>,
+    #[serde(rename = "question__hide")]
+    question_hide: bool,
+    total_acs: u32,
+    total_submitted: u32,
+    pub frontend_question_id: u32,
+    is_new_question: bool,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Difficulty {
+    level: u32,
+}
+
+impl Display for Difficulty {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        match self.level {
+            1 => f.write_str("Easy"),
+            2 => f.write_str("Medium"),
+            3 => f.write_str("Hard"),
+            _ => f.write_str("Unknown"),
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 00000000..55b0298f
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,5 @@
+#[macro_use]
+pub mod util;
+
+pub mod solution;
+pub mod problem;
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 00000000..6fecf106
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,362 @@
+#[macro_use]
+extern crate serde_derive;
+#[macro_use]
+extern crate serde_json;
+
+mod fetcher;
+
+use crate::fetcher::{CodeDefinition, Problem};
+use regex::Regex;
+use std::env;
+use std::fs;
+use std::fs::File;
+use std::io;
+use std::io::{BufRead, Write};
+use std::path::Path;
+
+use futures::executor::block_on;
+use futures::executor::ThreadPool;
+use futures::future::join_all;
+use futures::stream::StreamExt;
+use futures::task::SpawnExt;
+use std::sync::{Arc, Mutex};
+
+/// main() helps to generate the submission template .rs
+fn main() {
+    println!("Welcome to leetcode-rust system.\n");
+    let mut initialized_ids = get_initialized_ids();
+    loop {
+        println!(
+            "Please enter a frontend problem id, \n\
+            or \"random\" to generate a random one, \n\
+            or \"solve $i\" to move problem to solution/, \n\
+            or \"all\" to initialize all problems \n"
+        );
+        let mut is_random = false;
+        let mut is_solving = false;
+        let mut id: u32 = 0;
+        let mut id_arg = String::new();
+        io::stdin()
+            .read_line(&mut id_arg)
+            .expect("Failed to read line");
+        let id_arg = id_arg.trim();
+
+        let random_pattern = Regex::new(r"^random$").unwrap();
+        let solving_pattern = Regex::new(r"^solve (\d+)$").unwrap();
+        let all_pattern = Regex::new(r"^all$").unwrap();
+
+        if random_pattern.is_match(id_arg) {
+            println!("You select random mode.");
+            id = generate_random_id(&initialized_ids);
+            is_random = true;
+            println!("Generate random problem: {}", &id);
+        } else if solving_pattern.is_match(id_arg) {
+            // solve a problem
+            // move it from problem/ to solution/
+            is_solving = true;
+            id = solving_pattern
+                .captures(id_arg)
+                .unwrap()
+                .get(1)
+                .unwrap()
+                .as_str()
+                .parse()
+                .unwrap();
+            deal_solving(&id);
+            break;
+        } else if all_pattern.is_match(id_arg) {
+            // deal all problems
+            let pool = ThreadPool::new().unwrap();
+            let mut tasks = vec![];
+            let problems = fetcher::get_problems().unwrap();
+            let mut mod_file_addon = Arc::new(Mutex::new(vec![]));
+            for problem_stat in problems.stat_status_pairs {
+                if initialized_ids.contains(&problem_stat.stat.frontend_question_id) {
+                    continue;
+                }
+                let mod_file_addon = mod_file_addon.clone();
+                tasks.push(
+                    pool.spawn_with_handle(async move {
+                        let problem = fetcher::get_problem_async(problem_stat).await;
+                        if problem.is_none() {
+                            return;
+                        }
+                        let problem = problem.unwrap();
+                        let code = problem
+                            .code_definition
+                            .iter()
+                            .find(|&d| d.value == "rust".to_string());
+                        if code.is_none() {
+                            println!("Problem {} has no rust version.", problem.question_id);
+                            return;
+                        }
+                        // not sure this can be async
+                        async {
+                            mod_file_addon.lock().unwrap().push(format!(
+                                "mod p{:04}_{};",
+                                problem.question_id,
+                                problem.title_slug.replace("-", "_")
+                            ));
+                        }
+                        .await;
+                        let code = code.unwrap();
+                        // not sure this can be async
+                        // maybe should use async-std io
+                        async { deal_problem(&problem, &code, false) }.await
+                    })
+                    .unwrap(),
+                );
+            }
+            block_on(join_all(tasks));
+            let mut lib_file = fs::OpenOptions::new()
+                .write(true)
+                .append(true)
+                .open("./src/problem/mod.rs")
+                .unwrap();
+            writeln!(lib_file, "{}", mod_file_addon.lock().unwrap().join("\n"));
+            break;
+        } else {
+            id = id_arg
+                .parse::<u32>()
+                .unwrap_or_else(|_| panic!("not a number: {}", id_arg));
+            if initialized_ids.contains(&id) {
+                println!("The problem you chose has been initialized in problem/");
+                continue;
+            }
+        }
+
+        let problem = fetcher::get_problem(id).unwrap_or_else(|| {
+            panic!(
+                "Error: failed to get problem #{} \
+                 (The problem may be paid-only or may not be exist).",
+                id
+            )
+        });
+        let code = problem
+            .code_definition
+            .iter()
+            .find(|&d| d.value == "rust".to_string());
+        if code.is_none() {
+            println!("Problem {} has no rust version.", &id);
+            initialized_ids.push(problem.question_id);
+            continue;
+        }
+        let code = code.unwrap();
+        deal_problem(&problem, &code, true);
+        break;
+    }
+}
+
+fn generate_random_id(except_ids: &[u32]) -> u32 {
+    use rand::Rng;
+    use std::fs;
+    let mut rng = rand::thread_rng();
+    loop {
+        let res: u32 = rng.gen_range(1, 1106);
+        if !except_ids.contains(&res) {
+            return res;
+        }
+        println!(
+            "Generate a random num ({}), but it is invalid (the problem may have been solved \
+             or may have no rust version). Regenerate..",
+            res
+        );
+    }
+}
+
+fn get_initialized_ids() -> Vec<u32> {
+    let content = fs::read_to_string("./src/problem/mod.rs").unwrap();
+    let id_pattern = Regex::new(r"p(\d{4})_").unwrap();
+    id_pattern
+        .captures_iter(&content)
+        .map(|x| x.get(1).unwrap().as_str().parse().unwrap())
+        .collect()
+}
+
+fn parse_extra_use(code: &str) -> String {
+    let mut extra_use_line = String::new();
+    // a linked-list problem
+    if code.contains("pub struct ListNode") {
+        extra_use_line.push_str("\nuse crate::util::linked_list::{ListNode, to_list};")
+    }
+    if code.contains("pub struct TreeNode") {
+        extra_use_line.push_str("\nuse crate::util::tree::{TreeNode, to_tree};")
+    }
+    if code.contains("pub struct Point") {
+        extra_use_line.push_str("\nuse crate::util::point::Point;")
+    }
+    extra_use_line
+}
+
+fn parse_problem_link(problem: &Problem) -> String {
+    format!("https://leetcode.com/problems/{}/", problem.title_slug)
+}
+
+fn parse_discuss_link(problem: &Problem) -> String {
+    format!(
+        "https://leetcode.com/problems/{}/discuss/?currentPage=1&orderBy=most_votes&query=",
+        problem.title_slug
+    )
+}
+
+fn insert_return_in_code(return_type: &str, code: &str) -> String {
+    let re = Regex::new(r"\{[ \n]+}").unwrap();
+    match return_type {
+        "ListNode" => re
+            .replace(&code, "{\n        Some(Box::new(ListNode::new(0)))\n    }")
+            .to_string(),
+        "ListNode[]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "TreeNode" => re
+            .replace(
+                &code,
+                "{\n        Some(Rc::new(RefCell::new(TreeNode::new(0))))\n    }",
+            )
+            .to_string(),
+        "boolean" => re.replace(&code, "{\n        false\n    }").to_string(),
+        "character" => re.replace(&code, "{\n        '0'\n    }").to_string(),
+        "character[][]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "double" => re.replace(&code, "{\n        0f64\n    }").to_string(),
+        "double[]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "int[]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "integer" => re.replace(&code, "{\n        0\n    }").to_string(),
+        "integer[]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "integer[][]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<String>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<TreeNode>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<boolean>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<double>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<integer>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<list<integer>>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<list<string>>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "list<string>" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "null" => code.to_string(),
+        "string" => re
+            .replace(&code, "{\n        String::new()\n    }")
+            .to_string(),
+        "string[]" => re.replace(&code, "{\n        vec![]\n    }").to_string(),
+        "void" => code.to_string(),
+        "NestedInteger" => code.to_string(),
+        "Node" => code.to_string(),
+        _ => code.to_string(),
+    }
+}
+
+fn build_desc(content: &str) -> String {
+    // TODO: fix this shit
+    content
+        .replace("<strong>", "")
+        .replace("</strong>", "")
+        .replace("<em>", "")
+        .replace("</em>", "")
+        .replace("</p>", "")
+        .replace("<p>", "")
+        .replace("<b>", "")
+        .replace("</b>", "")
+        .replace("<pre>", "")
+        .replace("</pre>", "")
+        .replace("<ul>", "")
+        .replace("</ul>", "")
+        .replace("<li>", "")
+        .replace("</li>", "")
+        .replace("<code>", "")
+        .replace("</code>", "")
+        .replace("<i>", "")
+        .replace("</i>", "")
+        .replace("<sub>", "")
+        .replace("</sub>", "")
+        .replace("</sup>", "")
+        .replace("<sup>", "^")
+        .replace("&nbsp;", " ")
+        .replace("&gt;", ">")
+        .replace("&lt;", "<")
+        .replace("&quot;", "\"")
+        .replace("&minus;", "-")
+        .replace("&#39;", "'")
+        .replace("\n\n", "\n")
+        .replace("\n", "\n * ")
+}
+
+fn deal_solving(id: &u32) {
+    let problem = fetcher::get_problem(*id).unwrap();
+    let file_name = format!(
+        "p{:04}_{}",
+        problem.question_id,
+        problem.title_slug.replace("-", "_")
+    );
+    let file_path = Path::new("./src/problem").join(format!("{}.rs", file_name));
+    // check problem/ existence
+    if !file_path.exists() {
+        panic!("problem does not exist");
+    }
+    // check solution/ no existence
+    let solution_name = format!(
+        "s{:04}_{}",
+        problem.question_id,
+        problem.title_slug.replace("-", "_")
+    );
+    let solution_path = Path::new("./src/solution").join(format!("{}.rs", solution_name));
+    if solution_path.exists() {
+        panic!("solution exists");
+    }
+    // rename/move file
+    fs::rename(file_path, solution_path).unwrap();
+    // remove from problem/mod.rs
+    let mod_file = "./src/problem/mod.rs";
+    let target_line = format!("mod {};", file_name);
+    let lines: Vec<String> = io::BufReader::new(File::open(mod_file).unwrap())
+        .lines()
+        .map(|x| x.unwrap())
+        .filter(|x| *x != target_line)
+        .collect();
+    fs::write(mod_file, lines.join("\n"));
+    // insert into solution/mod.rs
+    let mut lib_file = fs::OpenOptions::new()
+        .append(true)
+        .open("./src/solution/mod.rs")
+        .unwrap();
+    writeln!(lib_file, "mod {};", solution_name);
+}
+
+fn deal_problem(problem: &Problem, code: &CodeDefinition, write_mod_file: bool) {
+    let file_name = format!(
+        "p{:04}_{}",
+        problem.question_id,
+        problem.title_slug.replace("-", "_")
+    );
+    let file_path = Path::new("./src/problem").join(format!("{}.rs", file_name));
+    if file_path.exists() {
+        panic!("problem already initialized");
+    }
+
+    let template = fs::read_to_string("./template.rs").unwrap();
+    let source = template
+        .replace("__PROBLEM_TITLE__", &problem.title)
+        .replace("__PROBLEM_DESC__", &build_desc(&problem.content))
+        .replace(
+            "__PROBLEM_DEFAULT_CODE__",
+            &insert_return_in_code(&problem.return_type, &code.default_code),
+        )
+        .replace("__PROBLEM_ID__", &format!("{}", problem.question_id))
+        .replace("__EXTRA_USE__", &parse_extra_use(&code.default_code))
+        .replace("__PROBLEM_LINK__", &parse_problem_link(problem))
+        .replace("__DISCUSS_LINK__", &parse_discuss_link(problem));
+
+    let mut file = fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .truncate(true)
+        .open(&file_path)
+        .unwrap();
+
+    file.write_all(source.as_bytes()).unwrap();
+    drop(file);
+
+    if write_mod_file {
+        let mut lib_file = fs::OpenOptions::new()
+            .write(true)
+            .append(true)
+            .open("./src/problem/mod.rs")
+            .unwrap();
+        writeln!(lib_file, "mod {};", file_name);
+    }
+}
diff --git a/src/problem/mod.rs b/src/problem/mod.rs
new file mode 100644
index 00000000..e69de29b
diff --git a/src/solution/mod.rs b/src/solution/mod.rs
new file mode 100644
index 00000000..bc982de9
--- /dev/null
+++ b/src/solution/mod.rs
@@ -0,0 +1,237 @@
+mod s0001_two_sum;
+mod s0002_add_two_numbers;
+mod s0003_longest_substring_without_repeating_characters;
+mod s0004_median_of_two_sorted_arrays;
+mod s0005_longest_palindromic_substring;
+mod s0006_zigzag_conversion;
+mod s0007_reverse_integer;
+mod s0008_string_to_integer_atoi;
+mod s0009_palindrome_number;
+mod s0010_regular_expression_matching;
+mod s0011_container_with_most_water;
+mod s0012_integer_to_roman;
+mod s0013_roman_to_integer;
+mod s0014_longest_common_prefix;
+mod s0015_3sum;
+mod s0016_3sum_closest;
+mod s0017_letter_combinations_of_a_phone_number;
+mod s0018_4sum;
+mod s0019_remove_nth_node_from_end_of_list;
+mod s0020_valid_parentheses;
+mod s0021_merge_two_sorted_lists;
+mod s0022_generate_parentheses;
+mod s0023_merge_k_sorted_lists;
+mod s0024_swap_nodes_in_pairs;
+mod s0025_reverse_nodes_in_k_group;
+mod s0026_remove_duplicates_from_sorted_array;
+mod s0027_remove_element;
+mod s0028_implement_strstr;
+mod s0029_divide_two_integers;
+mod s0030_substring_with_concatenation_of_all_words;
+mod s0031_next_permutation;
+mod s0032_longest_valid_parentheses;
+mod s0033_search_in_rotated_sorted_array;
+mod s0034_find_first_and_last_position_of_element_in_sorted_array;
+mod s0035_search_insert_position;
+mod s0036_valid_sudoku;
+mod s0037_sudoku_solver;
+mod s0038_count_and_say;
+mod s0039_combination_sum;
+mod s0040_combination_sum_ii;
+mod s0041_first_missing_positive;
+mod s0042_trapping_rain_water;
+mod s0043_multiply_strings;
+mod s0044_wildcard_matching;
+mod s0045_jump_game_ii;
+mod s0046_permutations;
+mod s0047_permutations_ii;
+mod s0048_rotate_image;
+mod s0049_group_anagrams;
+mod s0050_powx_n;
+mod s0051_n_queens;
+mod s0052_n_queens_ii;
+mod s0053_maximum_subarray;
+mod s0054_spiral_matrix;
+mod s0055_jump_game;
+mod s0056_merge_intervals;
+mod s0057_insert_interval;
+mod s0058_length_of_last_word;
+mod s0059_spiral_matrix_ii;
+mod s0060_permutation_sequence;
+mod s0061_rotate_list;
+mod s0062_unique_paths;
+mod s0063_unique_paths_ii;
+mod s0064_minimum_path_sum;
+mod s0065_valid_number;
+mod s0066_plus_one;
+mod s0067_add_binary;
+mod s0068_text_justification;
+mod s0069_sqrtx;
+mod s0070_climbing_stairs;
+mod s0071_simplify_path;
+mod s0072_edit_distance;
+mod s0073_set_matrix_zeroes;
+mod s0074_search_a_2d_matrix;
+mod s0075_sort_colors;
+mod s0076_minimum_window_substring;
+mod s0077_combinations;
+mod s0078_subsets;
+mod s0079_word_search;
+mod s0080_remove_duplicates_from_sorted_array_ii;
+mod s0081_search_in_rotated_sorted_array_ii;
+mod s0082_remove_duplicates_from_sorted_list_ii;
+mod s0083_remove_duplicates_from_sorted_list;
+mod s0084_largest_rectangle_in_histogram;
+mod s0085_maximal_rectangle;
+mod s0086_partition_list;
+mod s0087_scramble_string;
+mod s0088_merge_sorted_array;
+mod s0089_gray_code;
+mod s0090_subsets_ii;
+mod s0091_decode_ways;
+mod s0092_reverse_linked_list_ii;
+mod s0093_restore_ip_addresses;
+mod s0094_binary_tree_inorder_traversal;
+mod s0095_unique_binary_search_trees_ii;
+mod s0096_unique_binary_search_trees;
+mod s0097_interleaving_string;
+mod s0098_validate_binary_search_tree;
+mod s0099_recover_binary_search_tree;
+mod s0100_same_tree;
+mod s0101_symmetric_tree;
+mod s0102_binary_tree_level_order_traversal;
+mod s0103_binary_tree_zigzag_level_order_traversal;
+mod s0104_maximum_depth_of_binary_tree;
+mod s0105_construct_binary_tree_from_preorder_and_inorder_traversal;
+mod s0106_construct_binary_tree_from_inorder_and_postorder_traversal;
+mod s0107_binary_tree_level_order_traversal_ii;
+mod s0108_convert_sorted_array_to_binary_search_tree;
+mod s0109_convert_sorted_list_to_binary_search_tree;
+mod s0110_balanced_binary_tree;
+mod s0111_minimum_depth_of_binary_tree;
+mod s0112_path_sum;
+mod s0113_path_sum_ii;
+mod s0114_flatten_binary_tree_to_linked_list;
+mod s0115_distinct_subsequences;
+mod s0118_pascals_triangle;
+mod s0119_pascals_triangle_ii;
+mod s0120_triangle;
+mod s0121_best_time_to_buy_and_sell_stock;
+mod s0122_best_time_to_buy_and_sell_stock_ii;
+mod s0123_best_time_to_buy_and_sell_stock_iii;
+mod s0124_binary_tree_maximum_path_sum;
+mod s0125_valid_palindrome;
+mod s0126_word_ladder_ii;
+mod s0127_word_ladder;
+mod s0128_longest_consecutive_sequence;
+mod s0129_sum_root_to_leaf_numbers;
+mod s0130_surrounded_regions;
+mod s0131_palindrome_partitioning;
+mod s0132_palindrome_partitioning_ii;
+mod s0134_gas_station;
+mod s0135_candy;
+mod s0136_single_number;
+mod s0137_single_number_ii;
+mod s0139_word_break;
+mod s0140_word_break_ii;
+mod s0143_reorder_list;
+mod s0144_binary_tree_preorder_traversal;
+mod s0145_binary_tree_postorder_traversal;
+mod s0146_lru_cache;
+mod s0147_insertion_sort_list;
+mod s0148_sort_list;
+mod s0149_max_points_on_a_line;
+mod s0150_evaluate_reverse_polish_notation;
+mod s0151_reverse_words_in_a_string;
+mod s0152_maximum_product_subarray;
+mod s0153_find_minimum_in_rotated_sorted_array;
+mod s0154_find_minimum_in_rotated_sorted_array_ii;
+mod s0155_min_stack;
+mod s0162_find_peak_element;
+mod s0164_maximum_gap;
+mod s0165_compare_version_numbers;
+mod s0166_fraction_to_recurring_decimal;
+mod s0167_two_sum_ii_input_array_is_sorted;
+mod s0168_excel_sheet_column_title;
+mod s0169_majority_element;
+mod s0171_excel_sheet_column_number;
+mod s0172_factorial_trailing_zeroes;
+mod s0173_binary_search_tree_iterator;
+mod s0174_dungeon_game;
+mod s0179_largest_number;
+mod s0187_repeated_dna_sequences;
+mod s0188_best_time_to_buy_and_sell_stock_iv;
+mod s0189_rotate_array;
+mod s0198_house_robber;
+mod s0199_binary_tree_right_side_view;
+mod s0200_number_of_islands;
+mod s0201_bitwise_and_of_numbers_range;
+mod s0202_happy_number;
+mod s0203_remove_linked_list_elements;
+mod s0204_count_primes;
+mod s0205_isomorphic_strings;
+mod s0206_reverse_linked_list;
+mod s0207_course_schedule;
+mod s0208_implement_trie_prefix_tree;
+mod s0209_minimum_size_subarray_sum;
+mod s0210_course_schedule_ii;
+mod s0211_add_and_search_word_data_structure_design;
+mod s0212_word_search_ii;
+mod s0213_house_robber_ii;
+mod s0214_shortest_palindrome;
+mod s0215_kth_largest_element_in_an_array;
+mod s0216_combination_sum_iii;
+mod s0217_contains_duplicate;
+mod s0218_the_skyline_problem;
+mod s0219_contains_duplicate_ii;
+mod s0220_contains_duplicate_iii;
+mod s0221_maximal_square;
+mod s0222_count_complete_tree_nodes;
+mod s0223_rectangle_area;
+mod s0224_basic_calculator;
+mod s0225_implement_stack_using_queues;
+mod s0226_invert_binary_tree;
+mod s0227_basic_calculator_ii;
+mod s0228_summary_ranges;
+mod s0229_majority_element_ii;
+mod s0230_kth_smallest_element_in_a_bst;
+mod s0231_power_of_two;
+mod s0232_implement_queue_using_stacks;
+mod s0233_number_of_digit_one;
+mod s0238_product_of_array_except_self;
+mod s0239_sliding_window_maximum;
+mod s0241_different_ways_to_add_parentheses;
+mod s0242_valid_anagram;
+mod s0257_binary_tree_paths;
+mod s0258_add_digits;
+mod s0260_single_number_iii;
+mod s0263_ugly_number;
+mod s0264_ugly_number_ii;
+mod s0268_missing_number;
+mod s0273_integer_to_english_words;
+mod s0274_h_index;
+mod s0275_h_index_ii;
+mod s0279_perfect_squares;
+mod s0282_expression_add_operators;
+mod s0283_move_zeroes;
+mod s0287_find_the_duplicate_number;
+mod s0289_game_of_life;
+mod s0290_word_pattern;
+mod s0292_nim_game;
+mod s0295_find_median_from_data_stream;
+mod s0299_bulls_and_cows;
+mod s0300_longest_increasing_subsequence;
+mod s0301_remove_invalid_parentheses;
+mod s0303_range_sum_query_immutable;
+mod s0304_range_sum_query_2d_immutable;
+mod s0306_additive_number;
+mod s0307_range_sum_query_mutable;
+mod s0309_best_time_to_buy_and_sell_stock_with_cooldown;
+mod s0310_minimum_height_trees;
+mod s0312_burst_balloons;
+mod s0313_super_ugly_number;
+mod s0509_fibonacci_number;
+mod s0704_binary_search;
+mod s0969_pancake_sorting;
+mod s1018_binary_prefix_divisible_by_5;
+mod s1046_last_stone_weight;
diff --git a/src/util/linked_list.rs b/src/util/linked_list.rs
new file mode 100644
index 00000000..37b18e3d
--- /dev/null
+++ b/src/util/linked_list.rs
@@ -0,0 +1,29 @@
+#[derive(PartialEq, Eq, Debug)]
+pub struct ListNode {
+    pub val: i32,
+    pub next: Option<Box<ListNode>>,
+}
+
+impl ListNode {
+    #[inline]
+    pub fn new(val: i32) -> Self {
+        ListNode { next: None, val }
+    }
+}
+
+// helper function for test
+pub fn to_list(vec: Vec<i32>) -> Option<Box<ListNode>> {
+    let mut current = None;
+    for &v in vec.iter().rev() {
+        let mut node = ListNode::new(v);
+        node.next = current;
+        current = Some(Box::new(node));
+    }
+    current
+}
+
+#[macro_export]
+macro_rules! linked {
+    ($($e:expr),*) => {to_list(vec![$($e.to_owned()), *])};
+    ($($e:expr,)*) => {to_list(vec![$($e.to_owned()), *])};
+}
diff --git a/src/util/mod.rs b/src/util/mod.rs
new file mode 100644
index 00000000..5a3e5744
--- /dev/null
+++ b/src/util/mod.rs
@@ -0,0 +1,8 @@
+#[macro_use]
+pub mod linked_list;
+#[macro_use]
+pub mod vec_string;
+#[macro_use]
+pub mod tree;
+#[macro_use]
+pub mod point;
diff --git a/src/util/point.rs b/src/util/point.rs
new file mode 100644
index 00000000..3af0c803
--- /dev/null
+++ b/src/util/point.rs
@@ -0,0 +1,23 @@
+#[derive(Debug, PartialEq, Eq)]
+pub struct Point {
+    pub x: i32,
+    pub y: i32,
+}
+
+impl Point {
+    #[inline]
+    pub fn new(x: i32, y: i32) -> Self {
+        Point { x, y }
+    }
+}
+
+#[macro_export]
+macro_rules! point {
+    ($($e:expr),*) => {
+        {
+            let vec = vec![$($e.to_owned()), *];
+            Point::new(vec[0], vec[1])
+        }
+    };
+    ($($e:expr,)*) => (point![$($x),*])
+}
diff --git a/src/util/testing.rs b/src/util/testing.rs
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/src/util/testing.rs
@@ -0,0 +1 @@
+
diff --git a/src/util/tree.rs b/src/util/tree.rs
new file mode 100644
index 00000000..dacda57d
--- /dev/null
+++ b/src/util/tree.rs
@@ -0,0 +1,57 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TreeNode {
+    pub val: i32,
+    pub left: Option<Rc<RefCell<TreeNode>>>,
+    pub right: Option<Rc<RefCell<TreeNode>>>,
+}
+
+impl TreeNode {
+    #[inline]
+    pub fn new(val: i32) -> Self {
+        TreeNode {
+            val,
+            left: None,
+            right: None,
+        }
+    }
+}
+
+pub fn to_tree(vec: Vec<Option<i32>>) -> Option<Rc<RefCell<TreeNode>>> {
+    use std::collections::VecDeque;
+    let head = Some(Rc::new(RefCell::new(TreeNode::new(vec[0].unwrap()))));
+    let mut queue = VecDeque::new();
+    queue.push_back(head.as_ref().unwrap().clone());
+
+    for children in vec[1..].chunks(2) {
+        let parent = queue.pop_front().unwrap();
+        if let Some(v) = children[0] {
+            parent.borrow_mut().left = Some(Rc::new(RefCell::new(TreeNode::new(v))));
+            queue.push_back(parent.borrow().left.as_ref().unwrap().clone());
+        }
+        if children.len() > 1 {
+            if let Some(v) = children[1] {
+                parent.borrow_mut().right = Some(Rc::new(RefCell::new(TreeNode::new(v))));
+                queue.push_back(parent.borrow().right.as_ref().unwrap().clone());
+            }
+        }
+    }
+    head
+}
+
+#[macro_export]
+macro_rules! tree {
+    () => {
+        None
+    };
+    ($($e:expr),*) => {
+        {
+            let vec = vec![$(stringify!($e)), *];
+            let vec = vec.into_iter().map(|v| v.parse::<i32>().ok()).collect::<Vec<_>>();
+            to_tree(vec)
+        }
+    };
+    ($($e:expr,)*) => {(tree![$($e),*])};
+}
diff --git a/src/util/vec_string.rs b/src/util/vec_string.rs
new file mode 100644
index 00000000..5b07068d
--- /dev/null
+++ b/src/util/vec_string.rs
@@ -0,0 +1,5 @@
+#[macro_export]
+macro_rules! vec_string {
+    ($($e:expr),*) => {vec![$($e.to_owned()), *]};
+    ($($e:expr,)*) => {vec![$($e.to_owned()), *]};
+}
diff --git a/template.rs b/template.rs
new file mode 100644
index 00000000..11411f01
--- /dev/null
+++ b/template.rs
@@ -0,0 +1,24 @@
+/**
+ * [__PROBLEM_ID__] __PROBLEM_TITLE__
+ *
+ * __PROBLEM_DESC__
+ */
+pub struct Solution {}__EXTRA_USE__
+
+// problem: __PROBLEM_LINK__
+// discuss: __DISCUSS_LINK__
+
+// submission codes start here
+
+__PROBLEM_DEFAULT_CODE__
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test___PROBLEM_ID__() {
+    }
+}