knossos 1.2.0

Rust library for generating and rendering mazes
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

pub struct ArenaTree {
    nodes: Vec<Node>,
}
#[derive(Debug)]
struct Node {
    _id: NodeId,
    parent: Option<NodeId>,
}

#[derive(Debug, Clone, Copy)]
pub struct NodeId(pub usize);

impl ArenaTree {
    pub const fn new() -> ArenaTree {
        ArenaTree { nodes: vec![] }
    }

    pub fn new_node(&mut self) -> NodeId {
        let next_idx = NodeId(self.nodes.len());

        self.nodes.push(Node {
            _id: next_idx,
            parent: None,
        });

        next_idx
    }

    pub fn connect(&mut self, id1: NodeId, id2: NodeId) {
        let root1 = self.root(id1);
        let root2 = self.root(id2);

        if root1.and(root2).is_none() {
            return;
        }

        if let Some(node) = self.nodes.get_mut(root2.unwrap().0) {
            node.parent = root1;
        }
    }

    pub fn connected(&self, id1: NodeId, id2: NodeId) -> bool {
        let root1 = self.root(id1);
        let root2 = self.root(id2);

        if root1.and(root2).is_none() {
            return false;
        }

        root1.unwrap().0 == root2.unwrap().0
    }

    fn root(&self, id: NodeId) -> Option<NodeId> {
        let node = self.nodes.get(id.0);
        node?;

        if let Some(parent) = node.unwrap().parent {
            self.root(parent)
        } else {
            Some(id)
        }
    }
}

impl Node {}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn unconnected_nodes() {
        let mut arena = ArenaTree::new();

        let node1 = arena.new_node();
        let node2 = arena.new_node();
        let node3 = arena.new_node();

        assert!(!arena.connected(node1, node2));
        assert!(!arena.connected(node1, node3));
    }

    #[test]
    fn connect_two_nodes() {
        let mut arena = ArenaTree::new();

        let node1 = arena.new_node();
        let node2 = arena.new_node();
        let node3 = arena.new_node();

        arena.connect(node1, node2);
        assert!(arena.connected(node1, node2));
        assert!(!arena.connected(node1, node3));
    }

    #[test]
    fn connect_three_nodes() {
        let mut arena = ArenaTree::new();

        let node1 = arena.new_node();
        let node2 = arena.new_node();
        let node3 = arena.new_node();

        arena.connect(node1, node2);
        arena.connect(node3, node2);

        assert!(arena.connected(node1, node2));
        assert!(arena.connected(node1, node3));
        assert!(arena.connected(node3, node2));
    }

    #[test]
    fn connect_one_none_node() {
        let mut arena = ArenaTree::new();
        let node1 = arena.new_node();

        arena.connect(node1, NodeId(2));
        assert!(!arena.connected(node1, NodeId(2)));

        arena.connect(NodeId(2), node1);
        assert!(!arena.connected(node1, NodeId(2)));
    }

    #[test]
    fn connect_two_none_node() {
        let arena = ArenaTree::new();
        arena.connected(NodeId(1), NodeId(2));
        assert!(!arena.connected(NodeId(1), NodeId(2)));
    }
}