diff --git a/examples/priority_queue_test.rs b/examples/priority_queue_test.rs
new file mode 100644
index 0000000..a8a739b
--- /dev/null
+++ b/examples/priority_queue_test.rs
@@ -0,0 +1,40 @@
+use factorio_blueprint::priority_queue::{fibonacci_heap::FibonacciHeap, PriorityQueue};
+use std::fmt::Debug;
+
+fn test_loop<P>()
+where
+    P: PriorityQueue<u16> + Debug,
+{
+    let mut input = String::new();
+
+    let mut p = P::new();
+
+    let mut handles = Vec::new();
+
+    loop {
+        input.clear();
+        std::io::stdin().read_line(&mut input);
+
+        let (cmd, arg) = input.trim().split_once(' ').unwrap_or((input.trim(), ""));
+        // dbg!(cmd, arg);
+
+        match cmd {
+            "i" => handles.push(p.insert(arg.parse::<u16>().unwrap())),
+            "m" => println!("{:?}", p.pop_min()),
+            "d" => {
+                let (a, b) = arg.split_once(' ').unwrap();
+                let h = &handles[a.parse::<usize>().unwrap()];
+                let n = b.parse::<u16>().unwrap();
+                p.decrease_key(h, |f| *f = n);
+            }
+            "p" => {
+                dbg!(&p);
+            }
+            _ => println!("Unknown command."),
+        }
+    }
+}
+
+fn main() {
+    test_loop::<FibonacciHeap<u16>>()
+}
diff --git a/examples/solve_belt2.rs b/examples/solve_belt2.rs
deleted file mode 100644
index 5b88e0d..0000000
--- a/examples/solve_belt2.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-use factorio_blueprint::belt_finding::{common::Position, Problem};
-
-fn main() {
-    let mut p = Problem::new(33, 13);
-
-    p.set_blocked_range(1, 3, 2, 5, true);
-    p.set_blocked_range(1, 7, 2, 9, true);
-
-    p.set_blocked(0, 3, true);
-    p.set_blocked(0, 8, true);
-
-    p.set_blocked_range(10, 0, 21, 2, true);
-    p.set_blocked_range(10, 5, 21, 7, true);
-    p.set_blocked_range(10, 10, 21, 12, true);
-
-    p.set_blocked_range(30, 3, 31, 5, true);
-    p.set_blocked_range(30, 7, 31, 9, true);
-    p.set_blocked(32, 3, true);
-    p.set_blocked(32, 9, true);
-
-    p.add_connection(Position::new(3, 3), Position::new(29, 7));
-    p.add_connection(Position::new(3, 4), Position::new(29, 9));
-    p.add_connection(Position::new(3, 5), Position::new(29, 8));
-
-    p.add_connection(Position::new(3, 7), Position::new(29, 3));
-    p.add_connection(Position::new(3, 8), Position::new(29, 5));
-    p.add_connection(Position::new(3, 9), Position::new(29, 4));
-
-    println!("{p}");
-    p.find_path();
-    println!("{p}");
-}
diff --git a/src/belt_finding/mod.rs b/src/belt_finding/mod.rs
index 666fc8b..feb017f 100644
--- a/src/belt_finding/mod.rs
+++ b/src/belt_finding/mod.rs
@@ -1,7 +1,9 @@
-use crate::graph::wheighted_graph::shortest_path::dijkstra;
 use crate::graph::wheighted_graph::WheightedGraph;
 use crate::misc::Map;
 use crate::priority_queue::BinaryHeap;
+use crate::{
+    graph::wheighted_graph::shortest_path::dijkstra, priority_queue::fibonacci_heap::FibonacciHeap,
+};
 use std::ops::Index;
 use termcolor::{Color, ColorSpec};
 
@@ -208,7 +210,7 @@ impl Problem {
         for i in 0..self.start.len() {
             self.calculate_wheights(i);
             let m = MapInternal { map: &self.map };
-            let p = dijkstra::<MapInternal, BinaryHeap<_>>(&m, self.start[i], self.end[i]);
+            let p = dijkstra::<MapInternal, FibonacciHeap<_>>(&m, self.start[i], self.end[i]);
 
             if let Some(p) = p {
                 self.path[i] = p;
diff --git a/src/graph/wheighted_graph/shortest_path.rs b/src/graph/wheighted_graph/shortest_path.rs
index a6142ce..27887f1 100644
--- a/src/graph/wheighted_graph/shortest_path.rs
+++ b/src/graph/wheighted_graph/shortest_path.rs
@@ -119,7 +119,7 @@ mod test {
         graph::wheighted_graph::{
             adjacency_list::WheightedAdjacencyList, shortest_path::dijkstra, WheightedGraph,
         },
-        priority_queue::BinaryHeap,
+        priority_queue::{fibonacci_heap::FibonacciHeap, BinaryHeap},
     };
 
     #[test]
@@ -162,6 +162,14 @@ mod test {
             dijkstra::<WheightedAdjacencyList, BinaryHeap<_>>(&a, 0, 6),
             None
         );
+        assert_eq!(
+            dijkstra::<WheightedAdjacencyList, FibonacciHeap<_>>(&a, 0, 4),
+            Some(vec![0, 1, 2, 5, 4])
+        );
+        assert_eq!(
+            dijkstra::<WheightedAdjacencyList, FibonacciHeap<_>>(&a, 0, 6),
+            None
+        );
     }
 
     struct Grid {
diff --git a/src/priority_queue/fibonacci_heap.rs b/src/priority_queue/fibonacci_heap.rs
index dca5da5..a181df0 100644
--- a/src/priority_queue/fibonacci_heap.rs
+++ b/src/priority_queue/fibonacci_heap.rs
@@ -1,186 +1,280 @@
+use std::fmt::Debug;
+
 use crate::misc::{Arena, ArenaKey};
 
 use super::PriorityQueue;
 
-#[derive(Debug)]
-struct FibonacciHeapObject<T> {
-    left: ArenaKey,
-    right: ArenaKey,
-    parent: Option<ArenaKey>,
-    child: Option<ArenaKey>,
-    rank: usize,
-    marked: bool,
-    data: T,
+type Index = u32;
+
+pub struct FibonacciHeap<I> {
+    min: Option<Index>,
+    data: Vec<Option<Node<I>>>,
+    free: Vec<Index>,
+    temp: [Option<Index>; 64],
+}
+
+impl<I: std::fmt::Debug> std::fmt::Debug for FibonacciHeap<I> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        struct PrintData<'a, I>(&'a Vec<Option<Node<I>>>);
+        impl<'a, I: Debug> Debug for PrintData<'a, I> {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                f.debug_map()
+                    .entries(self.0.iter().enumerate().filter_map(|d| {
+                        if let (i, Some(c)) = d {
+                            Some((i, c))
+                        } else {
+                            None
+                        }
+                    }))
+                    .finish()
+            }
+        }
+        f.debug_struct("FibonacciHeap")
+            .field("min", &self.min)
+            .field("data", &PrintData(&self.data))
+            .field("free", &self.free)
+            .finish()
+    }
 }
 
 #[derive(Debug)]
-pub struct FibonacciHeap<T> {
-    arena: Arena<FibonacciHeapObject<T>>,
-    min: Option<ArenaKey>,
-    update_rank: Vec<Option<ArenaKey>>,
+pub struct FibonacciHeapHandle(Index);
+
+#[derive(Debug)]
+struct Node<I> {
+    item: I,
+    parent: Index,
+    left: Index,
+    right: Index,
+    child: Index,
+    mark: bool,
+    rank: u16,
 }
 
-pub struct FibonacciHeapHandle(ArenaKey);
+impl<I> Node<I> {
+    fn new(item: I) -> Self {
+        Self {
+            item,
+            parent: 0,
+            left: 0,
+            right: 0,
+            child: 0,
+            mark: false,
+            rank: 0,
+        }
+    }
+}
 
-impl<T> PriorityQueue<T> for FibonacciHeap<T>
+impl<I> FibonacciHeap<I>
 where
-    T: std::cmp::Ord,
+    I: PartialOrd,
+{
+    fn add_to_list(&mut self, list: Index, i: Index) {
+        let right = self.get(list).right;
+        let n = self.get_mut(i);
+        n.right = right;
+        n.left = list;
+        self.get_mut(right).left = i;
+        self.get_mut(list).right = i;
+    }
+
+    fn remove_from_list(&mut self, i: Index) -> Option<Index> {
+        let left = self.get(i).left;
+        if left == i {
+            return None;
+        }
+
+        let right = self.get(i).right;
+
+        self.get_mut(left).right = right;
+        self.get_mut(right).left = left;
+
+        Some(right)
+    }
+
+    fn insert_tree(&mut self, i: Index) {
+        if let Some(min) = self.min {
+            self.add_to_list(min, i);
+
+            self.get_mut(i).parent = i;
+
+            if self.get(i).item < self.get(min).item {
+                self.min = Some(i);
+            }
+        } else {
+            let m = self.get_mut(i);
+            m.parent = i;
+            m.left = i;
+            m.right = i;
+            self.min = Some(i);
+        }
+    }
+
+    fn union(&mut self, a: Index, b: Index) -> Index {
+        let min;
+        let max;
+
+        if self.get(a).item < self.get(b).item {
+            min = a;
+            max = b;
+        } else {
+            min = b;
+            max = a;
+        }
+
+        if self.get(min).rank == 0 {
+            self.get_mut(min).child = max;
+            self.get_mut(min).rank = 1;
+            let m = self.get_mut(max);
+            m.parent = min;
+            m.left = max;
+            m.right = max;
+        } else {
+            self.get_mut(max).parent = min;
+            self.add_to_list(self.get(min).child, max);
+            self.get_mut(min).rank += 1;
+        }
+
+        min
+    }
+    fn insert_temp(&mut self, i: Index) {
+        let rank = self.get(i).rank;
+        if let Some(t) = self.temp[rank as usize].take() {
+            let m = self.union(t, i);
+
+            self.insert_temp(m);
+        } else {
+            self.temp[rank as usize] = Some(i);
+        }
+    }
+
+    fn insert_data(&mut self, data: I) -> Index {
+        if let Some(i) = self.free.pop() {
+            self.data[i as usize] = Some(Node::new(data));
+            i
+        } else {
+            let i = self.data.len() as Index;
+            self.data.push(Some(Node::new(data)));
+            i
+        }
+    }
+
+    fn get(&self, i: Index) -> &Node<I> {
+        self.data.get(i as usize).unwrap().as_ref().unwrap()
+    }
+
+    fn get_mut(&mut self, i: Index) -> &mut Node<I> {
+        self.data.get_mut(i as usize).unwrap().as_mut().unwrap()
+    }
+
+    fn remove_data(&mut self, i: Index) -> I {
+        let n = self.data[i as usize].take().unwrap();
+
+        self.free.push(i);
+
+        n.item
+    }
+
+    fn cut(&mut self, i: Index) {
+        if self.get(i).item < self.get(self.min.unwrap()).item {
+            self.min = Some(i);
+        }
+        let parent = self.get(i).parent;
+        if parent == i {
+            return;
+        }
+        let c = self.remove_from_list(i);
+        if self.get(parent).rank > 1 {
+            self.get_mut(parent).child = c.unwrap();
+        }
+        self.get_mut(parent).rank -= 1;
+
+        self.add_to_list(self.min.unwrap(), i);
+        self.get_mut(i).mark = false;
+        self.get_mut(i).parent = i;
+
+        if self.get(parent).mark {
+            self.cut(parent);
+        } else {
+            self.get_mut(parent).mark = true;
+        }
+    }
+}
+
+impl<I> PriorityQueue<I> for FibonacciHeap<I>
+where
+    I: PartialOrd,
 {
     type Handle = FibonacciHeapHandle;
 
     fn new() -> Self {
-        todo!()
+        FibonacciHeap {
+            min: None,
+            data: Vec::new(),
+            free: Vec::new(),
+            temp: [None; 64],
+        }
     }
 
-    fn insert(&mut self, item: T) -> Self::Handle {
-        let h = self.arena.insert(FibonacciHeapObject {
-            left: ArenaKey::default(),
-            right: ArenaKey::default(),
-            parent: None,
-            child: None,
-            rank: 0,
-            marked: false,
-            data: item,
-        });
+    fn insert(&mut self, item: I) -> Self::Handle {
+        let i = self.insert_data(item);
 
-        self.insert_tree(h);
+        self.insert_tree(i);
 
-        FibonacciHeapHandle(h)
+        FibonacciHeapHandle(i)
     }
 
-    fn pop_min(&mut self) -> Option<T> {
-        if let Some(k) = self.min.take() {
-            let o = self.arena.remove(k);
-
-            if let Some(child) = o.child {
-                let mut p = child;
+    fn pop_min(&mut self) -> Option<I> {
+        if let Some(min) = self.min.take() {
+            if self.get(min).rank != 0 {
+                let mut c = self.get(min).child;
                 loop {
-                    self.arena.get_mut(&p).parent = None;
-                    self.arena.get_mut(&p).marked = false;
-                    let t = self.arena.get(&p).right;
-
-                    self.insert_tree(p);
-
-                    p = t;
-
-                    if p == child {
+                    let t = c;
+                    c = self.get(c).right;
+                    self.add_to_list(min, t);
+                    self.get_mut(t).parent = t;
+                    self.get_mut(t).mark = false;
+                    if c == self.get(min).child {
                         break;
                     }
                 }
             }
+            if let Some(m) = self.remove_from_list(min) {
+                let mut c = m;
+                loop {
+                    let t = c;
+                    c = self.get(c).right;
+                    self.insert_temp(t);
+                    if c == m {
+                        break;
+                    }
+                }
 
-            if o.left != o.right {
-                self.arena.get_mut(&o.left).right = o.right;
-                self.arena.get_mut(&o.right).left = o.left;
-                self.update_min(o.left);
+                for i in 0..self.temp.len() {
+                    if let Some(i) = self.temp[i].take() {
+                        if let Some(min) = self.min {
+                            self.add_to_list(min, i);
+                            if self.get(i).item < self.get(min).item {
+                                self.min = Some(i);
+                            }
+                        } else {
+                            self.get_mut(i).left = i;
+                            self.get_mut(i).right = i;
+                            self.min = Some(i);
+                        }
+                    }
+                }
             }
 
-            Some(o.data)
+            Some(self.remove_data(min))
         } else {
             None
         }
     }
 
-    fn decrease_key(&mut self, _handle: &Self::Handle, _f: impl Fn(&mut T)) {
-        todo!()
-    }
-}
-
-impl<T> FibonacciHeap<T>
-where
-    T: std::cmp::Ord,
-{
-    fn insert_tree(&mut self, h: ArenaKey) {
-        if let Some(h_min) = self.min {
-            let h_last = self.arena.get(&h_min).left;
-
-            self.arena.get_mut(&h_min).left = h;
-
-            self.arena.get_mut(&h).left = h_last;
-            self.arena.get_mut(&h).right = h_min;
-
-            self.arena.get_mut(&h_last).right = h;
-
-            if self.arena.get(&h).data < self.arena.get(&h_min).data {
-                self.min = Some(h)
-            }
-        } else {
-            self.arena.get_mut(&h).left = h;
-            self.arena.get_mut(&h).right = h;
-
-            self.min = Some(h);
-        }
-    }
-
-    fn update_min(&mut self, mut h: ArenaKey) {
-        let h_start = h;
-
-        loop {
-            let next_h = self.arena.get(&h).right;
-
-            self.add_to_update_rank(h);
-
-            h = next_h;
-            if h == h_start {
-                break;
-            }
-        }
-
-        let mut prev = None;
-        // let mut start = None;
-
-        for h in &mut self.update_rank {
-            if let Some(h) = h.take() {
-                if let Some(p) = prev {
-                    self.arena.get_mut(&h).left = p;
-                    self.arena.get_mut(&p).right = h;
-                } else {
-                    prev = Some(h);
-                    // start = Some(h);
-                }
-                if let Some(m) = self.min {
-                    if self.arena.get(&h).data < self.arena.get(&m).data {
-                        self.min = Some(h);
-                    }
-                } else {
-                    self.min = Some(h);
-                }
-            }
-        }
-    }
-
-    fn add_to_update_rank(&mut self, h: ArenaKey) {
-        let rank = self.arena.get(&h).rank;
-
-        while self.update_rank.len() + 1 < rank {
-            self.update_rank.push(None)
-        }
-
-        if let Some(o) = self.update_rank.get_mut(rank).unwrap().take() {
-            if let Some(child) = self.arena.get(&h).child {
-                let last = self.arena.get(&child).left;
-
-                self.arena.get_mut(&child).left = h;
-                self.arena.get_mut(&last).right = h;
-
-                self.arena.get_mut(&o).parent = Some(h);
-                self.arena.get_mut(&o).marked = false;
-                self.arena.get_mut(&o).left = last;
-                self.arena.get_mut(&o).right = child;
-            } else {
-                self.arena.get_mut(&h).child = Some(o);
-
-                self.arena.get_mut(&o).parent = Some(h);
-                self.arena.get_mut(&o).marked = false;
-                self.arena.get_mut(&o).left = o;
-                self.arena.get_mut(&o).right = o;
-            }
-
-            self.arena.get_mut(&h).rank += 1;
-
-            self.add_to_update_rank(h);
-        } else {
-            *self.update_rank.get_mut(rank).unwrap() = Some(h);
-        }
+    fn decrease_key(&mut self, handle: &Self::Handle, f: impl Fn(&mut I)) {
+        let h = self.get_mut(handle.0);
+        f(&mut h.item);
+        self.cut(handle.0);
     }
 }
diff --git a/src/priority_queue/mod.rs b/src/priority_queue/mod.rs
index 7a960a7..b622c6b 100644
--- a/src/priority_queue/mod.rs
+++ b/src/priority_queue/mod.rs
@@ -100,6 +100,8 @@ where
 
 #[cfg(test)]
 mod tests {
+    use super::fibonacci_heap::FibonacciHeap;
+    use super::BinaryHeap;
     use super::PriorityQueue;
 
     macro_rules! test_generics {
@@ -124,12 +126,14 @@ mod tests {
 
             #[test]
             fn $fun() {
-                super::$fun::<super::super::$gen<usize>>();
+                super::super::$fun::<super::super::$gen<usize>>();
             }
         }
     }
 
-    test_generics!(basic_generic decrease_key_generic; BinaryHeap);
+    mod test_macro {
+        test_generics!(basic_generic decrease_key_generic; BinaryHeap FibonacciHeap);
+    }
 
     fn basic_generic<T: PriorityQueue<usize>>() {
         let mut q = T::new();