From 708aafb362b64fbb2e002718f739b5d04e06931c Mon Sep 17 00:00:00 2001
From: "Dr. Matthias Ratajczak" <m.ratajczak@hzdr.de>
Date: Tue, 27 Jun 2023 18:57:46 +0200
Subject: [PATCH] add 95 (WIP)

---
 src/euler95/Cargo.toml  |  8 +++++++
 src/euler95/src/main.rs | 51 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 src/euler95/Cargo.toml
 create mode 100644 src/euler95/src/main.rs

diff --git a/src/euler95/Cargo.toml b/src/euler95/Cargo.toml
new file mode 100644
index 0000000..38eb5dd
--- /dev/null
+++ b/src/euler95/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "euler95"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/src/euler95/src/main.rs b/src/euler95/src/main.rs
new file mode 100644
index 0000000..0bf37d4
--- /dev/null
+++ b/src/euler95/src/main.rs
@@ -0,0 +1,51 @@
+const MAX: usize = 1_000;
+
+fn main() {
+    let mut numbers: Vec<_> = (0_usize..MAX + 1).map(|_| true).collect();
+
+    let mut chains = vec![];
+
+    let mut i = 0_usize;
+    loop {
+        if i > MAX {
+            break;
+        }
+        let mut num = if numbers[i] {
+            numbers[i] = false;
+            i
+        } else {
+            i += 1;
+            continue;
+        };
+
+        let mut maybe_chain = vec![];
+
+        loop {
+            let next: usize = get_proper_divisors(num).sum();
+            if next > MAX {
+                break;
+            }
+
+            if !numbers[next] {
+                if maybe_chain.contains(&next) {
+                    chains.push(maybe_chain);
+                }
+                break;
+            }
+
+            numbers[next] = false;
+            maybe_chain.push(num);
+
+            num = next;
+        }
+
+        i += 1;
+    }
+
+    dbg!(chains);
+}
+
+fn get_proper_divisors(x: usize) -> impl Iterator<Item = usize> {
+    let limit = x / 2 + 1;
+    (1..limit).filter(move |i| x % *i == 0)
+}