diff options
| -rw-r--r-- | src/libcollections/binary_heap.rs | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/src/libcollections/binary_heap.rs b/src/libcollections/binary_heap.rs index 04cffeddc5f..effd4ebb316 100644 --- a/src/libcollections/binary_heap.rs +++ b/src/libcollections/binary_heap.rs @@ -66,7 +66,7 @@ //! // to each node. This implementation isn't memory-efficient as it may leave duplicate //! // nodes in the queue. It also uses `usize::MAX` as a sentinel value, //! // for a simpler implementation. -//! fn shortest_path(adj_list: &Vec<Vec<Edge>>, start: usize, goal: usize) -> usize { +//! fn shortest_path(adj_list: &Vec<Vec<Edge>>, start: usize, goal: usize) -> Option<usize> { //! // dist[node] = current shortest distance from `start` to `node` //! let mut dist: Vec<_> = (0..adj_list.len()).map(|_| usize::MAX).collect(); //! @@ -79,7 +79,7 @@ //! // Examine the frontier with lower cost nodes first (min-heap) //! while let Some(State { cost, position }) = heap.pop() { //! // Alternatively we could have continued to find all shortest paths -//! if position == goal { return cost; } +//! if position == goal { return Some(cost); } //! //! // Important as we may have already found a better way //! if cost > dist[position] { continue; } @@ -99,7 +99,7 @@ //! } //! //! // Goal not reachable -//! usize::MAX +//! None //! } //! //! fn main() { @@ -140,11 +140,11 @@ //! // Node 4 //! vec![]]; //! -//! assert_eq!(shortest_path(&graph, 0, 1), 1); -//! assert_eq!(shortest_path(&graph, 0, 3), 3); -//! assert_eq!(shortest_path(&graph, 3, 0), 7); -//! assert_eq!(shortest_path(&graph, 0, 4), 5); -//! assert_eq!(shortest_path(&graph, 4, 0), usize::MAX); +//! assert_eq!(shortest_path(&graph, 0, 1), Some(1)); +//! assert_eq!(shortest_path(&graph, 0, 3), Some(3)); +//! assert_eq!(shortest_path(&graph, 3, 0), Some(7)); +//! assert_eq!(shortest_path(&graph, 0, 4), Some(5)); +//! assert_eq!(shortest_path(&graph, 4, 0), None); //! } //! ``` |