diff --git a/src/complexagent.rs b/src/complexagent.rs
index 8fe81e2..77a0951 100644
--- a/src/complexagent.rs
+++ b/src/complexagent.rs
@@ -140,8 +140,7 @@ impl FutureMoves {
                 .arena
                 .iter()
                 .enumerate()
-                .filter(|(_, node)| self.depth_of(node.parent) == depth)
-                .map(|(idx, _)| idx)
+                .filter_map(|(idx, node)| (self.depth_of(node.parent) == depth).then_some(idx))
                 .collect();
 
             for idx in nodes_at_depth {
@@ -180,24 +179,21 @@ impl FutureMoves {
                 .arena
                 .iter()
                 .enumerate()
-                .filter(|(_, node)| node.parent.is_none())
-                .map(|(idx, _)| idx)
+                .filter_map(|(idx, node)| node.parent.is_none().then_some(idx))
                 .collect(),
         };
 
         root_nodes
             .into_iter()
-            .max_by_key(|&idx| self.arena[idx].value)
-            .map(|idx| (self.arena[idx].i, self.arena[idx].j))
+            .map(|idx| &self.arena[idx])
+            .max_by_key(|x| x.value)
+            .map(|x| (x.i, x.j))
     }
 
     pub fn update_root(&mut self, i: usize, j: usize) -> bool {
-        let new_root = self
-            .arena
-            .iter()
-            .enumerate()
-            .find(|(_, node)| node.parent == self.current_root && node.i == i && node.j == j)
-            .map(|(idx, _)| idx);
+        let new_root = self.arena.iter().enumerate().find_map(|(idx, node)| {
+            (node.parent == self.current_root && node.i == i && node.j == j).then_some(idx)
+        });
 
         if let Some(root) = new_root {
             self.current_root = Some(root);