divide repository in src and lib

src/euler11/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "euler11"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/euler11/grid.txt

@@ -0,0 +1,20 @@
+08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
+49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
+81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
+52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
+22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
+24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
+32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
+67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
+24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
+21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
+78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
+16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
+86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
+19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
+04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
+88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
+04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
+20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
+20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
+01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48

src/euler11/src/main.rs

@@ -0,0 +1,192 @@
+use std::{fmt::Debug, fs};
+
+const LENGTH: usize = 4;
+
+type Data = u32;
+type Neighbours = Vec<Coordinate>;
+
+struct Coordinate {
+    x: usize,
+    y: usize,
+}
+
+impl Coordinate {
+    fn new(x: usize, y: usize) -> Self {
+        Self { x, y }
+    }
+}
+
+impl Debug for Coordinate {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let inner = &format!("{},{}", self.x, self.y);
+        f.write_str(inner)
+    }
+}
+
+struct Grid {
+    grid: Vec<Vec<Data>>,
+    nx: usize,
+    ny: usize,
+    curr_x: usize,
+    curr_y: usize,
+    curr_direction: Direction,
+    done: bool,
+}
+
+impl Grid {
+    fn from_file(filename: &str) -> Self {
+        let grid: Vec<Vec<_>> = fs::read_to_string(filename)
+            .unwrap()
+            .split_terminator('\n')
+            .map(|line| {
+                line.split_whitespace()
+                    .map(|cell| cell.parse::<u8>().unwrap() as Data)
+                    .collect()
+            })
+            .collect();
+        let ny = grid.len();
+        let nx = grid[0].len();
+        Grid {
+            grid,
+            nx,
+            ny,
+            curr_x: 0,
+            curr_y: 0,
+            curr_direction: Direction::None,
+            done: false,
+        }
+    }
+
+    fn run(&mut self) {
+        let mut largest = 0;
+        loop {
+            if let Some(coordinates) = self.next() {
+                let value = coordinates.iter().map(|c| self.grid[c.y][c.x]).product();
+                if value > largest {
+                    largest = value;
+                }
+            }
+            if self.done {
+                break;
+            }
+        }
+        println!("{largest}");
+    }
+
+    fn advance_index(&mut self) {
+        if self.curr_x == self.nx - 1 {
+            self.curr_x = 0;
+            self.curr_y += 1;
+            if self.curr_y == self.ny {
+                self.done = true;
+            }
+        } else {
+            self.curr_x += 1;
+        }
+    }
+
+    fn get_neighbours(&self) -> Option<Neighbours> {
+        match self.curr_direction {
+            Direction::Down => self.get_neighbours_down(),
+            Direction::Right => self.get_neighbours_right(),
+            Direction::DiagonalUp => self.get_neighbours_diag_up(),
+            Direction::DiagonalDown => self.get_neighbours_diag_down(),
+            Direction::None => unreachable!(),
+        }
+    }
+
+    fn get_neighbours_down(&self) -> Option<Neighbours> {
+        let max_y = self.curr_y + LENGTH;
+        if max_y > self.ny {
+            None
+        } else {
+            Some(
+                (self.curr_y..max_y)
+                    .map(|y| Coordinate::new(self.curr_x, y))
+                    .collect(),
+            )
+        }
+    }
+
+    fn get_neighbours_right(&self) -> Option<Neighbours> {
+        let max_x = self.curr_x + LENGTH;
+        if max_x > self.nx {
+            None
+        } else {
+            Some(
+                (self.curr_x..max_x)
+                    .map(|x| Coordinate::new(x, self.curr_y))
+                    .collect(),
+            )
+        }
+    }
+
+    fn get_neighbours_diag_up(&self) -> Option<Neighbours> {
+        let max_x = self.curr_x + LENGTH;
+        let min_y = self.curr_y.wrapping_sub(LENGTH);
+        if max_x > self.nx || min_y > self.ny {
+            None
+        } else {
+            Some(
+                (self.curr_x..max_x)
+                    .zip(self.curr_y..min_y)
+                    .map(|(x, y)| Coordinate::new(x, y))
+                    .collect(),
+            )
+        }
+    }
+
+    fn get_neighbours_diag_down(&self) -> Option<Neighbours> {
+        let max_x = self.curr_x + LENGTH;
+        let max_y = self.curr_y + LENGTH;
+        if max_x > self.nx || max_y > self.ny {
+            None
+        } else {
+            Some(
+                (self.curr_x..max_x)
+                    .zip(self.curr_y..max_y)
+                    .map(|(x, y)| Coordinate::new(x, y))
+                    .collect(),
+            )
+        }
+    }
+}
+
+impl Iterator for Grid {
+    type Item = Neighbours;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let has_wrapped;
+        (self.curr_direction, has_wrapped) = self.curr_direction.next();
+        if has_wrapped {
+            self.advance_index();
+        };
+        self.get_neighbours()
+    }
+}
+
+#[derive(Debug)]
+enum Direction {
+    None,
+    Down,
+    Right,
+    DiagonalUp,
+    DiagonalDown,
+}
+
+impl Direction {
+    fn next(&self) -> (Self, bool) {
+        match self {
+            Direction::None => (Direction::Down, false),
+            Direction::Down => (Direction::Right, false),
+            Direction::Right => (Direction::DiagonalUp, false),
+            Direction::DiagonalUp => (Direction::DiagonalDown, false),
+            Direction::DiagonalDown => (Direction::Down, true),
+        }
+    }
+}
+
+fn main() {
+    let mut grid = Grid::from_file("grid.txt");
+    grid.run();
+}

src/euler49/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "euler49"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/euler49/src/main.rs

@@ -0,0 +1,120 @@
+use std::collections::{HashMap, HashSet};
+
+type Int = i64;
+const MIN_VALUE: Int = 2;
+const MAX_VALUE: Int = 10_000;
+const SIZE: usize = (MAX_VALUE - MIN_VALUE) as usize;
+type Array = [bool; SIZE];
+type Solution = [Int; 3];
+
+fn main() {
+    println!("Getting prime numbers up to {}", MAX_VALUE);
+    let primes = Primes::from_array(get_prime_numbers_array());
+    println!("Starting to iterate ...");
+    let result = find_using_iter(&primes);
+    for item in result {
+        println!("{item}");
+    }
+}
+
+fn get_prime_numbers_array() -> Array {
+    // Sieve of Eratosthenes
+    let mut result = [true; SIZE];
+    for number_to_check in MIN_VALUE..(MAX_VALUE / 2) {
+        let mut last_number = number_to_check;
+        loop {
+            let current_number = last_number + number_to_check;
+            if current_number >= MAX_VALUE {
+                break;
+            }
+            result[(current_number - MIN_VALUE) as usize] = false;
+            last_number = current_number;
+        }
+    }
+    result
+}
+
+struct Primes {
+    vector: Vec<Int>,
+    set: HashSet<Int>,
+}
+impl Primes {
+    fn from_array(array: Array) -> Primes {
+        let mut vector = Vec::new();
+        let mut set = HashSet::new();
+        for number in MIN_VALUE..MAX_VALUE {
+            if array[(number - MIN_VALUE) as usize] {
+                vector.push(number);
+                set.insert(number);
+            }
+        }
+        Primes { vector, set }
+    }
+}
+
+fn find_using_iter(primes: &Primes) -> Solution {
+    for p1 in primes.vector.iter() {
+        let p2 = p1 + 3330;
+        let p3 = p2 + 3330;
+        if primes.set.contains(&p2) && primes.set.contains(&p3) {
+            let candidate = [*p1, p2, p3];
+            if satisfies_checks(&candidate) && candidate[0] != 1487 {
+                return candidate;
+            }
+        }
+    }
+    panic!()
+}
+
+fn satisfies_checks(candidates: &Solution) -> bool {
+    let vec: Vec<_> = candidates.iter().map(get_amount_of_digits).collect();
+    vec[0] == vec[1] && vec[0] == vec[2]
+}
+
+fn get_amount_of_digits(x: &Int) -> HashMap<i32, usize> {
+    let mut map = get_new_map();
+    x.to_string()
+        .chars()
+        .map(|c| c.to_digit(10).unwrap() as i32)
+        .for_each(|n| {
+            map.insert(n, map.get(&n).unwrap() + 1).unwrap();
+        });
+    map
+}
+
+fn get_new_map() -> HashMap<i32, usize> {
+    (0..=9).into_iter().zip([0; 10]).collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{get_amount_of_digits, get_new_map, satisfies_checks, Solution};
+
+    #[test]
+    fn test_get_amount_of_digits() {
+        let x = 4731;
+        let hs = get_amount_of_digits(&x);
+        let mut reference = get_new_map();
+        reference.insert(4, 1);
+        reference.insert(7, 1);
+        reference.insert(3, 1);
+        reference.insert(1, 1);
+        assert_eq!(hs, reference);
+
+        let x = 4777;
+        let hs = get_amount_of_digits(&x);
+        let mut reference = get_new_map();
+        reference.insert(4, 1);
+        reference.insert(7, 3);
+        assert_eq!(hs, reference);
+    }
+
+    #[test]
+    fn test_satisfies_checks() {
+        let input: Solution = [1234, 3241, 4321];
+        assert!(satisfies_checks(&input));
+
+        let input: Solution = [1254, 3241, 4321];
+        assert!(!satisfies_checks(&input));
+    }
+}

src/euler50/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "euler50"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[profile.release]
+lto = true
+opt-level = 3

src/euler50/src/main.rs

@@ -0,0 +1,113 @@
+use std::collections::HashSet;
+
+// you will probably need to incrase the stack limit
+// $ ulimit -s
+// $ ulimit -s 32768
+
+type Int = i64;
+const MIN_VALUE: Int = 2;
+const MAX_VALUE: Int = 1_000_000;
+const SIZE: usize = (MAX_VALUE - MIN_VALUE) as usize;
+type Array = [bool; SIZE];
+
+fn main() {
+    println!("Getting prime numbers up to {}", MAX_VALUE);
+    let primes = Primes::from_array(get_prime_numbers_array());
+    println!("Starting to iterate ...");
+    let result = find_using_iter(&primes).unwrap();
+    println!(
+        "{:?} / sum: {} / len: {}",
+        result,
+        sum_of_vector(result),
+        result.len()
+    );
+}
+
+fn get_prime_numbers_array() -> Array {
+    // Sieve of Eratosthenes
+    let mut result = [true; SIZE];
+    for number_to_check in MIN_VALUE..(MAX_VALUE / 2) {
+        let mut last_number = number_to_check;
+        loop {
+            let current_number = last_number + number_to_check;
+            if current_number >= MAX_VALUE {
+                break;
+            }
+            result[(current_number - MIN_VALUE) as usize] = false;
+            last_number = current_number;
+        }
+    }
+    result
+}
+
+fn sum_of_vector(vector: &[Int]) -> Int {
+    vector.iter().sum()
+}
+
+struct Primes {
+    vector: Vec<Int>,
+    set: HashSet<Int>,
+}
+
+struct PrimesIter<'a> {
+    primes: &'a Primes,
+    current_min: usize,
+    current_len: usize,
+}
+
+impl<'a> Iterator for PrimesIter<'a> {
+    type Item = &'a [Int];
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let result = &self.primes.vector[self.current_min..(self.current_min + self.current_len)];
+        if result.iter().sum::<Int>() > MAX_VALUE {
+            self.decrement_search_length();
+            return self.next();
+        }
+        if self.current_min + self.current_len < self.primes.vector.len() {
+            self.current_min += 1;
+        } else {
+            self.decrement_search_length();
+        }
+        Some(result)
+    }
+}
+
+impl<'a> PrimesIter<'a> {
+    fn decrement_search_length(&mut self) {
+        self.current_min = 0;
+        self.current_len -= 1;
+        println!("{}", self.current_len);
+    }
+}
+
+impl Primes {
+    fn iter(&self) -> PrimesIter {
+        PrimesIter {
+            primes: self,
+            current_min: 0,
+            current_len: self.vector.len(),
+        }
+    }
+
+    fn from_array(array: Array) -> Primes {
+        let mut vector = Vec::new();
+        let mut set = HashSet::new();
+        for number in MIN_VALUE..MAX_VALUE {
+            if array[(number - MIN_VALUE) as usize] {
+                vector.push(number);
+                set.insert(number);
+            }
+        }
+        Primes { vector, set }
+    }
+}
+
+fn find_using_iter(primes: &'_ Primes) -> Option<&'_ [Int]> {
+    for subvector in primes.iter() {
+        if primes.set.contains(&sum_of_vector(subvector)) {
+            return Some(subvector);
+        }
+    }
+    None
+}

src/euler51/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "euler51"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+primes = {version = "*", path = "../../lib/primes"}
+combination = {version = "*", path = "../../lib/combination"}

src/euler51/src/main.rs

@@ -0,0 +1,133 @@
+extern crate combination;
+extern crate primes;
+
+use combination::PositionCombinations;
+use primes::Primes;
+
+type Int = u64;
+
+// EXAMPLE 1
+// const MIN_VALUE: Int = 10;
+// const MAX_VALUE: Int = 99;
+// const LENGTH: usize = 2;
+// const MIN_LENGTH: usize = 1;
+
+// OWN TEST
+// const MIN_VALUE: Int = 100;
+// const MAX_VALUE: Int = 999;
+// const LENGTH: usize = 3;
+// const MIN_LENGTH: usize = 2;
+
+// EXAMPLE 2
+// const MIN_VALUE: Int = 10_000;
+// const MAX_VALUE: Int = 99_999;
+// const LENGTH: usize = 5;
+// const MIN_LENGTH: usize = 2;
+
+// FINAL
+const MIN_VALUE: Int = 100_000;
+const MAX_VALUE: Int = 999_999;
+const LENGTH: usize = 6;
+const MIN_LENGTH: usize = 2;
+
+const MAX_LENGTH: usize = LENGTH - 1;
+const DIGITS: [u8; 10] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+
+fn main() {
+    let all_primes = Primes::get_between(MIN_VALUE, MAX_VALUE);
+    let mut best_of_all_combinations = vec![];
+    for pattern in PositionCombinations::new(MIN_LENGTH, MAX_LENGTH, LENGTH) {
+        let mut best_this_combination = vec![];
+        let mut primes_to_check = all_primes.clone();
+        while let Some(first) = primes_to_check.pop() {
+            let mut primes_matching_pattern = vec![];
+            let digits = first.to_digits();
+            for digit in DIGITS {
+                let could_be_prime = digits
+                    .iter()
+                    .zip(pattern.clone())
+                    .map(|(d, b)| if b { digit } else { *d })
+                    .collect::<Vec<u8>>()
+                    .to_num();
+                if primes_to_check.contains(&could_be_prime) || could_be_prime == first {
+                    primes_matching_pattern.push(could_be_prime);
+                }
+            }
+            if primes_matching_pattern.len() > 2 {
+                best_this_combination.push(primes_matching_pattern)
+            }
+        }
+        if !best_this_combination.is_empty() {
+            best_of_all_combinations.push(get_longest(best_this_combination, false));
+        }
+    }
+    println!("{:#?}", get_longest(best_of_all_combinations, false));
+}
+
+fn get_longest(mut vec: Vec<Vec<Int>>, print: bool) -> Vec<Int> {
+    if vec.is_empty() {
+        panic!("cannot give the longest element of an empty vector")
+    }
+    if print {
+        println!("{:#?}", vec);
+    }
+    vec.sort_by_key(|c| c.len());
+    let length = vec.last().unwrap().len();
+    vec.into_iter().find(|v| v.len() == length).unwrap()
+}
+
+trait ToString {
+    fn to_string(&self) -> String;
+}
+
+impl ToString for Vec<u8> {
+    fn to_string(&self) -> String {
+        self.iter().map(|d| d.to_string()).collect()
+    }
+}
+
+trait ToDigits {
+    fn to_digits(&self) -> Vec<u8>;
+}
+
+trait ToNum {
+    fn to_num(&self) -> Int;
+}
+
+impl ToDigits for Int {
+    fn to_digits(&self) -> Vec<u8> {
+        self.to_string()
+            .chars()
+            .map(|x| x.to_digit(10).unwrap() as u8)
+            .collect()
+    }
+}
+
+impl ToNum for Vec<u8> {
+    fn to_num(&self) -> Int {
+        let mut result = 0;
+        let mut position = 1;
+        for digit in self.iter().rev() {
+            result += *digit as Int * position;
+            position *= 10;
+        }
+        result
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{ToDigits, ToNum};
+
+    #[test]
+    fn test_digits_to_num() {
+        let digits = vec![5, 7, 3, 8, 1];
+        assert_eq!(digits.to_num(), 57381);
+    }
+
+    #[test]
+    fn test_num_to_digits() {
+        let num = 83371;
+        assert_eq!(num.to_digits(), vec![8, 3, 3, 7, 1]);
+    }
+}