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| 1 | +use std::cmp::min; |
| 2 | + |
| 3 | +pub struct Solution {} |
| 4 | + |
| 5 | +impl Solution { |
| 6 | + pub fn network_delay_time(times: Vec<Vec<i32>>, n: i32, k: i32) -> i32 { |
| 7 | + use std::cmp::Reverse; |
| 8 | + use std::collections::BinaryHeap; |
| 9 | + use std::collections::HashMap; |
| 10 | + use std::collections::HashSet; |
| 11 | + |
| 12 | + #[derive(PartialEq, Eq, PartialOrd, Ord)] |
| 13 | + pub struct Edge { |
| 14 | + weight: i32, |
| 15 | + node: i32, |
| 16 | + } |
| 17 | + |
| 18 | + let mut visited: HashSet<i32> = HashSet::new(); |
| 19 | + let mut edges: HashMap<i32, Vec<Edge>> = HashMap::new(); |
| 20 | + |
| 21 | + for val in times { |
| 22 | + let (u, v, w) = (val[0], val[1], val[2]); |
| 23 | + |
| 24 | + let edge = Edge { weight: w, node: v }; |
| 25 | + |
| 26 | + if edges.contains_key(&u) { |
| 27 | + edges.entry(u).and_modify(|val| val.push(edge)); |
| 28 | + } else { |
| 29 | + edges.insert(u, vec![edge]); |
| 30 | + } |
| 31 | + } |
| 32 | + |
| 33 | + let mut min_heap: BinaryHeap<Reverse<Edge>> = BinaryHeap::new(); |
| 34 | + let mut res = 0; |
| 35 | + |
| 36 | + min_heap.push(Reverse(Edge { weight: 0, node: k })); |
| 37 | + |
| 38 | + while !min_heap.is_empty() { |
| 39 | + let edge = min_heap.pop().unwrap().0; |
| 40 | + |
| 41 | + if visited.contains(&edge.node) { |
| 42 | + continue; |
| 43 | + } |
| 44 | + visited.insert(edge.node); |
| 45 | + res = edge.weight; |
| 46 | + |
| 47 | + if let Some(edges) = edges.get(&edge.node) { |
| 48 | + for e in edges { |
| 49 | + if !visited.contains(&e.node) { |
| 50 | + min_heap.push(Reverse(Edge { |
| 51 | + weight: e.weight + res, |
| 52 | + node: e.node, |
| 53 | + })); |
| 54 | + } |
| 55 | + } |
| 56 | + } |
| 57 | + } |
| 58 | + |
| 59 | + if res == 0 || visited.len() != n as usize { |
| 60 | + return -1; |
| 61 | + } |
| 62 | + res |
| 63 | + } |
| 64 | +} |
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