diff --git a/src/euler31/src/main.rs b/src/euler31/src/main.rs
index bd8ed7e..8dd9fa4 100644
--- a/src/euler31/src/main.rs
+++ b/src/euler31/src/main.rs
@@ -1,163 +1,114 @@
 #![allow(dead_code)]
-use std::ops::Index;
+use std::{cmp::Reverse, collections::HashSet};
 
 const VALUE: u8 = 200;
 
 type Values = Vec<u8>;
 
 fn main() {
-    // let head = Tree::new(200);
+    let x = vec![VALUE];
+    let mut cases = HashSet::new();
+    cases.insert(x.clone());
+    solve(x, &mut cases, -1);
+    let mut cases_ordered: Vec<_> = cases.iter().collect();
+    cases_ordered.sort_unstable_by_key(|v| v.len());
+    for case in cases_ordered {
+        println!("{}", case.show());
+    }
+    println!("{}", cases.len());
 }
 
-#[derive(Debug, PartialEq)]
-struct Node {
-    values: Values,
-    nodes: Vec<Node>,
-}
-
-impl Node {
-    fn new(value: u8) -> Self {
-        Self {
-            values: vec![value],
-            nodes: vec![],
-        }
+fn solve(x: Values, cases: &mut HashSet<Values>, max_depth: isize) {
+    // println!("solving {}", x.show());
+    if max_depth == 0 {
+        return;
     }
-
-    fn new_vec(values: Values) -> Self {
-        Self {
-            values,
-            nodes: vec![],
-        }
-    }
-
-    fn get_value(&self, index: usize) -> Option<&u8> {
-        self.values.get(index)
-    }
-
-    fn iter(&mut self) {
-        if !self.nodes.is_empty() {
-            self.nodes.iter_mut().for_each(|n| n.iter())
-        } else {
-            let mut previous: Option<Vec<Values>> = None;
-            let mut offset = 0;
-            for (i, value) in self.values.iter().enumerate() {
-                let divided = divide_value(*value);
-
-                let use_existing_data = previous.is_none();
-                println!();
-                println!();
-                println!();
-                for (j, combination) in divided.iter().enumerate() {
-                    let mut new_vec;
-                    let offset;
-                    if use_existing_data {
-                        println!("existing");
-                        new_vec = self.values.clone();
-                        offset = 0;
-                    } else {
-                        println!("previous");
-                        new_vec = previous.as_ref().unwrap()[j].clone();
-                        offset = new_vec.len() - self.values.len();
-                    }
-                    println!();
-                    println!("{}", i + offset);
-                    println!("{new_vec:#?}");
-                    println!("{combination:#?}");
-
-                    new_vec.splice(i + offset..i + offset + 1, combination.clone());
-                    println!("{new_vec:#?}");
-                    if previous.is_none() {
-                        previous = Some(vec![new_vec.clone()]);
-                    } else {
-                        let mut new = previous.unwrap().clone();
-                        new.push(new_vec.clone());
-                        previous = Some(new);
-                    }
-                    debug_assert_eq!(new_vec.iter().sum::<u8>(), VALUE);
-                    self.nodes.push(Node::new_vec(new_vec));
-                }
+    for (i, val) in x.iter().enumerate() {
+        for variant in divide(*val) {
+            let mut copy = x.clone();
+            copy.splice(i..i + 1, variant);
+            debug_assert_eq!(copy.iter().sum::<u8>(), VALUE);
+            // copy.sort_unstable();
+            // copy.sort_unstable_by_key(|&i| Reverse(i));
+            // println!("{}", copy.show());
+            let mut sorted = copy.clone();
+            sorted.sort_unstable();
+            if cases.contains(&sorted) {
+                // eprintln!("already seen: {}", copy.show());
+                continue;
+            } else {
+                cases.insert(sorted);
+                solve(copy, cases, max_depth - 1)
             }
         }
     }
 }
 
-fn divide_value(x: u8) -> Vec<Values> {
+trait Display {
+    fn show(&self) -> String;
+}
+
+impl Display for Values {
+    fn show(&self) -> String {
+        self.iter()
+            .map(|i| i.to_string())
+            .reduce(|mut accum, elem| {
+                accum.push_str(", ");
+                accum.push_str(&elem);
+                accum
+            })
+            .unwrap()
+    }
+}
+
+fn divide(x: u8) -> Vec<Values> {
     if x == 200 {
         vec![vec![100, 100]]
     } else if x == 100 {
         vec![vec![50, 50]]
-    } else {
-        // x == 50
+    } else if x == 50 {
         vec![vec![20, 20, 10], vec![20, 10, 10, 10], vec![10; 5]]
-    }
-}
-
-impl Index<usize> for Node {
-    type Output = Node;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self.nodes[index]
+    } else if x == 20 {
+        vec![vec![10, 10]]
+    } else if x == 10 {
+        vec![vec![5, 5]]
+    } else if x == 5 {
+        vec![vec![2, 2, 1], vec![2, 1, 1, 1], vec![1; 5]]
+    } else if x == 2 {
+        vec![vec![1, 1]]
+    } else {
+        vec![vec![x]]
     }
 }
 
 #[cfg(test)]
 mod test {
-    // use crate::Node;
-    use crate::Node;
+    use crate::solve;
+    use std::collections::HashSet;
+
+    use crate::VALUE;
 
     #[test]
-    fn test_new() {
-        let tree = Node::new(200);
-        assert_eq!(tree.values, [200]);
-        assert_eq!(tree.nodes.len(), 0);
+    fn test_1() {
+        let x = vec![VALUE];
+        let mut hs = HashSet::new();
+        hs.insert(x.clone());
+        solve(x, &mut hs, 1);
+        assert_eq!(hs.len(), 2);
+        assert!(hs.contains(&vec![VALUE]));
+        assert!(hs.contains(&vec![100, 100]));
     }
 
     #[test]
-    fn test_iter() {
-        let mut tree = Node::new(200);
-        tree.iter();
-        assert_eq!(tree.nodes.len(), 1);
-        assert_eq!(tree.nodes[0].values, vec![100, 100]);
-    }
-
-    #[test]
-    fn test_iter_2() {
-        let mut tree = Node::new(200);
-        tree.iter();
-        tree.iter();
-        assert_eq!(tree.nodes[0][0].values, vec![50, 50, 100]);
-        assert_eq!(tree.nodes[0][1].values, vec![50; 4]);
-        assert!(tree.nodes[0].get_value(2).is_none());
-    }
-
-    #[test]
-    fn test_iter_3() {
-        let mut tree = Node::new(200);
-        tree.iter();
-        tree.iter();
-        tree.iter();
-        assert_eq!(tree.nodes[0][0][0].values, vec![20, 20, 10, 50, 100]);
-        assert_eq!(tree.nodes[0][0][1].values, vec![20, 10, 10, 10, 50, 100]);
-        assert_eq!(
-            tree.nodes[0][0][2].values,
-            vec![10, 10, 10, 10, 10, 50, 100]
-        );
-        assert_eq!(
-            tree.nodes[0][0][3].values,
-            vec![20, 20, 10, 20, 20, 10, 100]
-        );
-        assert_eq!(
-            tree.nodes[0][0][4].values,
-            vec![20, 10, 10, 10, 20, 10, 10, 10, 100]
-        );
-        assert_eq!(
-            tree.nodes[0][0][5].values,
-            vec![10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 100]
-        );
-        assert_eq!(
-            tree.nodes[0][0][6].values,
-            vec![10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 50, 50]
-        );
-        println!("{}", tree.nodes[0][0].nodes.len())
+    fn test_2() {
+        let x = vec![VALUE];
+        let mut hs = HashSet::new();
+        hs.insert(x.clone());
+        solve(x, &mut hs, 3);
+        assert_eq!(hs.len(), 4);
+        assert!(hs.contains(&vec![VALUE]));
+        assert!(hs.contains(&vec![100, 100]));
+        assert!(hs.contains(&vec![100, 50, 50]));
+        assert!(hs.contains(&vec![50, 50, 50, 50]));
     }
 }