Wrote program for Day 21

README.md

@@ -67,7 +67,7 @@ We encourage you to share your progress and ask questions in the Discussions sec
 | Day #18       | [Unique Paths](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-03/Day-18_Unique-Paths)                          | :white_check_mark:      |
 | Day #19       | [URL Shortener](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-03/Day-19_URL-Shortener)                         | :white_check_mark:      |
 | Day #20       | [API Challenge](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-03/Day-20_API-Challenge)                         | :white_check_mark:      |
-| Day #21       | [Random Maze Generator](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-03/Day-21_Random-Maze-Generator)                 | :white_large_square:      |
+| Day #21       | [Random Maze Generator](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-03/Day-21_Random-Maze-Generator)                 | :white_check_mark:      |
 | Day #22       | [Marcio Mellos Challenge](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-04/Day-22_Marcio-Mellos-Challenge)               | :white_large_square:      |
 | Day #23       | [The Dining Philosophers](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-04/Day-23_The-Dining_Philosophers)               | :white_large_square:      |
 | Day #24       | [The Josephus Problem](https://github.com/LiveGray/100-Days-Of-Rust/tree/main/Week-04/Day-24_The-Josephus-Problem)                  | :white_large_square:      |

Week-03/Day-21_Random-Maze-Generator/day21/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "day21"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

Week-03/Day-21_Random-Maze-Generator/day21/src/lib.rs

@@ -0,0 +1,99 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+pub fn draw_maze(height: usize, width: usize) -> String {
+    let mut maze = vec![vec![(false, false, false); width]; height];
+    let mut rng = Rng::new();
+
+    bfs_make_maze(
+        (
+            rng.random_number(0, height as u128) as usize,
+            rng.random_number(0, width as u128) as usize,
+        ),
+        &mut maze,
+    );
+
+    let mut res = "+---".repeat(width) + "+";
+    for c in 0..height {
+        res = format!("{}\n|", res);
+        for r in maze.get(c).unwrap() {
+            res = format!("{}   ", res);
+            if r.1 {
+                res = format!("{} ", res);
+            } else {
+                res = format!("{}|", res);
+            }
+        }
+        res = format!("{}\n+", res);
+        for r in maze.get(c).unwrap() {
+            if r.0 {
+                res = format!("{}   +", res);
+            } else {
+                res = format!("{}---+", res);
+            }
+        }
+    }
+
+    res
+}
+
+fn bfs_make_maze(position: (usize, usize), maze: &mut Vec<Vec<(bool, bool, bool)>>) {
+    maze[position.0][position.1].2 = true;
+    if position.1 + 1 < maze[0].len() && !maze[position.0][position.1 + 1].2 {
+        let mut new_position = position;
+        new_position.1 += 1;
+        maze[position.0][position.1].1 = true;
+        bfs_make_maze(new_position, maze);
+    }
+
+    if position.1 > 0 && !maze[position.0][position.1 - 1].2 {
+        let mut new_position = position;
+        new_position.1 -= 1;
+        maze[new_position.0][new_position.1].1 = true;
+        bfs_make_maze(new_position, maze);
+    }
+    if position.0 + 1 < maze.len() && !maze[position.0 + 1][position.1].2 {
+        let mut new_position = position;
+        new_position.0 += 1;
+        maze[position.0][position.1].0 = true;
+        bfs_make_maze(new_position, maze);
+    }
+    if position.0 > 0 && !maze[position.0 - 1][position.1].2 {
+        let mut new_position = position;
+        new_position.0 -= 1;
+        maze[new_position.0][new_position.1].0 = true;
+        bfs_make_maze(new_position, maze);
+    }
+}
+
+pub struct Rng {
+    seed: u128,
+}
+
+impl Rng {
+    pub fn new() -> Rng {
+        let time_since_epoch = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("Error in getting time")
+            .as_millis();
+        Rng {
+            seed: time_since_epoch,
+        }
+    }
+
+    fn linear_congruent_generator(&mut self, a: u128, c: u128, m: u128) -> u128 {
+        let result = (a * self.seed + c) % m;
+        self.seed = result;
+        result
+    }
+
+    pub fn random_number(&mut self, from: u128, to: u128) -> u128 {
+        let random_number = self.linear_congruent_generator(1103515245, 12345, 2u128.pow(31));
+        (random_number % (to - from)) + from
+    }
+}
+
+impl Default for Rng {
+    fn default() -> Self {
+        Self::new()
+    }
+}

Week-03/Day-21_Random-Maze-Generator/day21/src/main.rs

@@ -0,0 +1,23 @@
+use day21::draw_maze;
+use std::io::{self, Write};
+
+fn read_number(output: &str) -> usize {
+    let mut buffer = String::new();
+
+    print!("{}", output);
+    io::stdout().flush().unwrap();
+
+    io::stdin()
+        .read_line(&mut buffer)
+        .expect("Failed to read line");
+
+    buffer.trim().parse().expect("Not a number")
+}
+
+fn main() {
+    let height = read_number("Enter height: ");
+    let width = read_number("Enter width: ");
+
+    let maze = draw_maze(height, width);
+    println!("{}", maze);
+}