35 lines
1.1 KiB
Rust
35 lines
1.1 KiB
Rust
use std::{collections::HashSet, hash::Hash};
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pub trait TreeDiff<'a> {
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type TreeKey: 'a + Hash + PartialEq + Eq + Copy;
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type ChildIter: Iterator<Item = &'a Self::TreeKey>;
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fn children(&self, key: &Self::TreeKey) -> Option<Self::ChildIter>;
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fn contains_slot(&self, slot: &Self::TreeKey) -> bool;
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// Find all nodes reachable from `root1`, excluding subtree at `root2`
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fn subtree_diff(&self, root1: Self::TreeKey, root2: Self::TreeKey) -> HashSet<Self::TreeKey> {
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if !self.contains_slot(&root1) {
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return HashSet::new();
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}
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let mut pending_keys = vec![root1];
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let mut reachable_set = HashSet::new();
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while !pending_keys.is_empty() {
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let current_key = pending_keys.pop().unwrap();
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if current_key == root2 {
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continue;
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}
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for child in self
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.children(¤t_key)
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.expect("slot was discovered earlier, must exist")
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{
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pending_keys.push(*child);
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}
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reachable_set.insert(current_key);
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}
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reachable_set
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}
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}
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