From 1c30f42704eca0caabb5e45b09bef817dac47932 Mon Sep 17 00:00:00 2001
From: "Dr. Matthias Ratajczak" <m.ratajczak@hzdr.de>
Date: Wed, 10 Aug 2022 19:56:49 +0200
Subject: [PATCH] add 51 WIP

---
 euler51/Cargo.toml    |  9 +++++++
 euler51/src/main.rs   | 14 +++++++++++
 euler51/src/primes.rs | 56 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)
 create mode 100644 euler51/Cargo.toml
 create mode 100644 euler51/src/main.rs
 create mode 100644 euler51/src/primes.rs

diff --git a/euler51/Cargo.toml b/euler51/Cargo.toml
new file mode 100644
index 0000000..ecc6b28
--- /dev/null
+++ b/euler51/Cargo.toml
@@ -0,0 +1,9 @@
+[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]
+num = "*"
diff --git a/euler51/src/main.rs b/euler51/src/main.rs
new file mode 100644
index 0000000..db9ad47
--- /dev/null
+++ b/euler51/src/main.rs
@@ -0,0 +1,14 @@
+mod primes;
+
+use crate::primes::Primes;
+
+type Int = i64;
+
+const MIN_VALUE: Int = 10_000_000;
+const MAX_VALUE: Int = 10_010_000;
+// const MAX_VALUE: Int = 99_999_999;
+
+fn main() {
+    let primes = Primes::get_between(MIN_VALUE, MAX_VALUE);
+    println!("{}", primes.vector[0]);
+}
diff --git a/euler51/src/primes.rs b/euler51/src/primes.rs
new file mode 100644
index 0000000..64bafe7
--- /dev/null
+++ b/euler51/src/primes.rs
@@ -0,0 +1,56 @@
+extern crate num;
+
+use num::FromPrimitive;
+use num::Num;
+use num::ToPrimitive;
+use std::collections::HashSet;
+use std::hash::Hash;
+
+pub struct Primes<T: Num + ToPrimitive> {
+    pub vector: Vec<T>,
+    pub set: HashSet<T>,
+}
+
+impl<T: Num + ToPrimitive + FromPrimitive + Hash + Eq + PartialEq + Copy> Primes<T> {
+    pub fn get_between(min_value: T, max_value: T) -> Self {
+        Self::from_array(
+            Self::get_prime_numbers_array(&min_value, &max_value),
+            &min_value,
+            &max_value,
+        )
+    }
+
+    fn from_array(array: Vec<bool>, min_value: &T, max_value: &T) -> Self {
+        let mut vector = Vec::new();
+        let mut set = HashSet::new();
+        let min_value_usize = min_value.to_usize().unwrap();
+        let max_value_usize = max_value.to_usize().unwrap();
+        for number in min_value_usize..max_value_usize {
+            if array[(number - min_value_usize) as usize] {
+                vector.push(FromPrimitive::from_usize(number).unwrap());
+                set.insert(FromPrimitive::from_usize(number).unwrap());
+            }
+        }
+        Primes { vector, set }
+    }
+
+    fn get_prime_numbers_array(min_value: &T, max_value: &T) -> Vec<bool> {
+        // Sieve of Eratosthenes
+        let mut result = Vec::with_capacity((*max_value - *min_value).to_usize().unwrap());
+
+        let max_value_usize = max_value.to_usize().unwrap();
+
+        for number_to_check in 2..(max_value_usize / 2) {
+            let mut last_number = number_to_check;
+            loop {
+                let current_number = last_number + number_to_check;
+                if current_number >= max_value_usize {
+                    break;
+                }
+                result[(current_number - 2) as usize] = false;
+                last_number = current_number;
+            }
+        }
+        result
+    }
+}