716 lines
22 KiB
Rust
716 lines
22 KiB
Rust
// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
//! A priority queue implemented with a binary heap.
|
|
//!
|
|
//! Insertions have `O(log n)` time complexity and checking or popping the largest element is
|
|
//! `O(1)`. Converting a vector to a priority queue can be done in-place, and has `O(n)`
|
|
//! complexity. A priority queue can also be converted to a sorted vector in-place, allowing it to
|
|
//! be used for an `O(n log n)` in-place heapsort.
|
|
//!
|
|
//! # Example
|
|
//!
|
|
//! This is a larger example which implements [Dijkstra's algorithm][dijkstra]
|
|
//! to solve the [shortest path problem][sssp] on a [directed graph][dir_graph].
|
|
//! It showcases how to use the `PriorityQueue` with custom types.
|
|
//!
|
|
//! [dijkstra]: http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm
|
|
//! [sssp]: http://en.wikipedia.org/wiki/Shortest_path_problem
|
|
//! [dir_graph]: http://en.wikipedia.org/wiki/Directed_graph
|
|
//!
|
|
//! ```
|
|
//! use std::collections::PriorityQueue;
|
|
//! use std::uint;
|
|
//!
|
|
//! #[deriving(Eq, PartialEq)]
|
|
//! struct State {
|
|
//! cost: uint,
|
|
//! position: uint
|
|
//! }
|
|
//!
|
|
//! // The priority queue depends on `Ord`.
|
|
//! // Explicitly implement the trait so the queue becomes a min-heap
|
|
//! // instead of a max-heap.
|
|
//! impl Ord for State {
|
|
//! fn cmp(&self, other: &State) -> Ordering {
|
|
//! // Notice that the we flip the ordering here
|
|
//! other.cost.cmp(&self.cost)
|
|
//! }
|
|
//! }
|
|
//!
|
|
//! // `PartialOrd` needs to be implemented as well.
|
|
//! impl PartialOrd for State {
|
|
//! fn partial_cmp(&self, other: &State) -> Option<Ordering> {
|
|
//! Some(self.cmp(other))
|
|
//! }
|
|
//! }
|
|
//!
|
|
//! // Each node is represented as an `uint`, for a shorter implementation.
|
|
//! struct Edge {
|
|
//! node: uint,
|
|
//! cost: uint
|
|
//! }
|
|
//!
|
|
//! // Dijkstra's shortest path algorithm.
|
|
//!
|
|
//! // Start at `start` and use `dist` to track the current shortest distance
|
|
//! // to each node. This implementation isn't memory efficient as it may leave duplicate
|
|
//! // nodes in the queue. It also uses `uint::MAX` as a sentinel value,
|
|
//! // for a simpler implementation.
|
|
//! fn shortest_path(adj_list: &Vec<Vec<Edge>>, start: uint, goal: uint) -> uint {
|
|
//! // dist[node] = current shortest distance from `start` to `node`
|
|
//! let mut dist = Vec::from_elem(adj_list.len(), uint::MAX);
|
|
//!
|
|
//! let mut pq = PriorityQueue::new();
|
|
//!
|
|
//! // We're at `start`, with a zero cost
|
|
//! *dist.get_mut(start) = 0u;
|
|
//! pq.push(State { cost: 0u, position: start });
|
|
//!
|
|
//! // Examine the frontier with lower cost nodes first (min-heap)
|
|
//! loop {
|
|
//! let State { cost, position } = match pq.pop() {
|
|
//! None => break, // empty
|
|
//! Some(s) => s
|
|
//! };
|
|
//!
|
|
//! // Alternatively we could have continued to find all shortest paths
|
|
//! if position == goal { return cost }
|
|
//!
|
|
//! // Important as we may have already found a better way
|
|
//! if cost > dist[position] { continue }
|
|
//!
|
|
//! // For each node we can reach, see if we can find a way with
|
|
//! // a lower cost going through this node
|
|
//! for edge in adj_list[position].iter() {
|
|
//! let next = State { cost: cost + edge.cost, position: edge.node };
|
|
//!
|
|
//! // If so, add it to the frontier and continue
|
|
//! if next.cost < dist[next.position] {
|
|
//! pq.push(next);
|
|
//! // Relaxation, we have now found a better way
|
|
//! *dist.get_mut(next.position) = next.cost;
|
|
//! }
|
|
//! }
|
|
//! }
|
|
//!
|
|
//! // Goal not reachable
|
|
//! uint::MAX
|
|
//! }
|
|
//!
|
|
//! fn main() {
|
|
//! // This is the directed graph we're going to use.
|
|
//! // The node numbers correspond to the different states,
|
|
//! // and the edge weights symbolises the cost of moving
|
|
//! // from one node to another.
|
|
//! // Note that the edges are one-way.
|
|
//! //
|
|
//! // 7
|
|
//! // +-----------------+
|
|
//! // | |
|
|
//! // v 1 2 |
|
|
//! // 0 -----> 1 -----> 3 ---> 4
|
|
//! // | ^ ^ ^
|
|
//! // | | 1 | |
|
|
//! // | | | 3 | 1
|
|
//! // +------> 2 -------+ |
|
|
//! // 10 | |
|
|
//! // +---------------+
|
|
//! //
|
|
//! // The graph is represented as an adjacency list where each index,
|
|
//! // corresponding to a node value, has a list of outgoing edges.
|
|
//! // Chosen for it's efficiency.
|
|
//! let graph = vec![
|
|
//! // Node 0
|
|
//! vec![Edge { node: 2, cost: 10 },
|
|
//! Edge { node: 1, cost: 1 }],
|
|
//! // Node 1
|
|
//! vec![Edge { node: 3, cost: 2 }],
|
|
//! // Node 2
|
|
//! vec![Edge { node: 1, cost: 1 },
|
|
//! Edge { node: 3, cost: 3 },
|
|
//! Edge { node: 4, cost: 1 }],
|
|
//! // Node 3
|
|
//! vec![Edge { node: 0, cost: 7 },
|
|
//! Edge { node: 4, cost: 2 }],
|
|
//! // 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), uint::MAX);
|
|
//! }
|
|
//! ```
|
|
|
|
#![allow(missing_doc)]
|
|
|
|
use core::prelude::*;
|
|
|
|
use core::default::Default;
|
|
use core::mem::{zeroed, replace, swap};
|
|
use core::ptr;
|
|
|
|
use {Mutable, MutableSeq};
|
|
use slice;
|
|
use vec::Vec;
|
|
|
|
/// A priority queue implemented with a binary heap.
|
|
///
|
|
/// This will be a max-heap.
|
|
#[deriving(Clone)]
|
|
pub struct PriorityQueue<T> {
|
|
data: Vec<T>,
|
|
}
|
|
|
|
impl<T: Ord> Collection for PriorityQueue<T> {
|
|
/// Returns the length of the queue.
|
|
fn len(&self) -> uint { self.data.len() }
|
|
}
|
|
|
|
impl<T: Ord> Mutable for PriorityQueue<T> {
|
|
/// Drops all items from the queue.
|
|
fn clear(&mut self) { self.data.truncate(0) }
|
|
}
|
|
|
|
impl<T: Ord> Default for PriorityQueue<T> {
|
|
#[inline]
|
|
fn default() -> PriorityQueue<T> { PriorityQueue::new() }
|
|
}
|
|
|
|
impl<T: Ord> PriorityQueue<T> {
|
|
/// Creates an empty `PriorityQueue` as a max-heap.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
/// let pq: PriorityQueue<uint> = PriorityQueue::new();
|
|
/// ```
|
|
pub fn new() -> PriorityQueue<T> { PriorityQueue{data: vec!(),} }
|
|
|
|
/// Creates an empty `PriorityQueue` with a specific capacity.
|
|
/// This preallocates enough memory for `capacity` elements,
|
|
/// so that the `PriorityQueue` does not have to be reallocated
|
|
/// until it contains at least that many values.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
/// let pq: PriorityQueue<uint> = PriorityQueue::with_capacity(10u);
|
|
/// ```
|
|
pub fn with_capacity(capacity: uint) -> PriorityQueue<T> {
|
|
PriorityQueue { data: Vec::with_capacity(capacity) }
|
|
}
|
|
|
|
/// Creates a `PriorityQueue` from a vector. This is sometimes called
|
|
/// `heapifying` the vector.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
/// let pq = PriorityQueue::from_vec(vec![9i, 1, 2, 7, 3, 2]);
|
|
/// ```
|
|
pub fn from_vec(xs: Vec<T>) -> PriorityQueue<T> {
|
|
let mut q = PriorityQueue{data: xs,};
|
|
let mut n = q.len() / 2;
|
|
while n > 0 {
|
|
n -= 1;
|
|
q.siftdown(n)
|
|
}
|
|
q
|
|
}
|
|
|
|
/// An iterator visiting all values in underlying vector, in
|
|
/// arbitrary order.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
/// let pq = PriorityQueue::from_vec(vec![1i, 2, 3, 4]);
|
|
///
|
|
/// // Print 1, 2, 3, 4 in arbitrary order
|
|
/// for x in pq.iter() {
|
|
/// println!("{}", x);
|
|
/// }
|
|
/// ```
|
|
pub fn iter<'a>(&'a self) -> Items<'a, T> {
|
|
Items { iter: self.data.iter() }
|
|
}
|
|
|
|
/// Returns the greatest item in a queue, or `None` if it is empty.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq = PriorityQueue::new();
|
|
/// assert_eq!(pq.top(), None);
|
|
///
|
|
/// pq.push(1i);
|
|
/// pq.push(5i);
|
|
/// pq.push(2i);
|
|
/// assert_eq!(pq.top(), Some(&5i));
|
|
///
|
|
/// ```
|
|
pub fn top<'a>(&'a self) -> Option<&'a T> {
|
|
if self.is_empty() { None } else { Some(&self.data[0]) }
|
|
}
|
|
|
|
#[deprecated="renamed to `top`"]
|
|
pub fn maybe_top<'a>(&'a self) -> Option<&'a T> { self.top() }
|
|
|
|
/// Returns the number of elements the queue can hold without reallocating.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let pq: PriorityQueue<uint> = PriorityQueue::with_capacity(100u);
|
|
/// assert!(pq.capacity() >= 100u);
|
|
/// ```
|
|
pub fn capacity(&self) -> uint { self.data.capacity() }
|
|
|
|
/// Reserves capacity for exactly `n` elements in the `PriorityQueue`.
|
|
/// Do nothing if the capacity is already sufficient.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq: PriorityQueue<uint> = PriorityQueue::new();
|
|
/// pq.reserve_exact(100u);
|
|
/// assert!(pq.capacity() == 100u);
|
|
/// ```
|
|
pub fn reserve_exact(&mut self, n: uint) { self.data.reserve_exact(n) }
|
|
|
|
/// Reserves capacity for at least `n` elements in the `PriorityQueue`.
|
|
/// Do nothing if the capacity is already sufficient.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq: PriorityQueue<uint> = PriorityQueue::new();
|
|
/// pq.reserve(100u);
|
|
/// assert!(pq.capacity() >= 100u);
|
|
/// ```
|
|
pub fn reserve(&mut self, n: uint) {
|
|
self.data.reserve(n)
|
|
}
|
|
|
|
/// Removes the greatest item from a queue and returns it, or `None` if it
|
|
/// is empty.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq = PriorityQueue::from_vec(vec![1i, 3]);
|
|
///
|
|
/// assert_eq!(pq.pop(), Some(3i));
|
|
/// assert_eq!(pq.pop(), Some(1i));
|
|
/// assert_eq!(pq.pop(), None);
|
|
/// ```
|
|
pub fn pop(&mut self) -> Option<T> {
|
|
match self.data.pop() {
|
|
None => { None }
|
|
Some(mut item) => {
|
|
if !self.is_empty() {
|
|
swap(&mut item, self.data.get_mut(0));
|
|
self.siftdown(0);
|
|
}
|
|
Some(item)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[deprecated="renamed to `pop`"]
|
|
pub fn maybe_pop(&mut self) -> Option<T> { self.pop() }
|
|
|
|
/// Pushes an item onto the queue.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq = PriorityQueue::new();
|
|
/// pq.push(3i);
|
|
/// pq.push(5i);
|
|
/// pq.push(1i);
|
|
///
|
|
/// assert_eq!(pq.len(), 3);
|
|
/// assert_eq!(pq.top(), Some(&5i));
|
|
/// ```
|
|
pub fn push(&mut self, item: T) {
|
|
self.data.push(item);
|
|
let new_len = self.len() - 1;
|
|
self.siftup(0, new_len);
|
|
}
|
|
|
|
/// Pushes an item onto a queue then pops the greatest item off the queue in
|
|
/// an optimized fashion.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq = PriorityQueue::new();
|
|
/// pq.push(1i);
|
|
/// pq.push(5i);
|
|
///
|
|
/// assert_eq!(pq.push_pop(3i), 5);
|
|
/// assert_eq!(pq.push_pop(9i), 9);
|
|
/// assert_eq!(pq.len(), 2);
|
|
/// assert_eq!(pq.top(), Some(&3i));
|
|
/// ```
|
|
pub fn push_pop(&mut self, mut item: T) -> T {
|
|
if !self.is_empty() && *self.top().unwrap() > item {
|
|
swap(&mut item, self.data.get_mut(0));
|
|
self.siftdown(0);
|
|
}
|
|
item
|
|
}
|
|
|
|
/// Pops the greatest item off a queue then pushes an item onto the queue in
|
|
/// an optimized fashion. The push is done regardless of whether the queue
|
|
/// was empty.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq = PriorityQueue::new();
|
|
///
|
|
/// assert_eq!(pq.replace(1i), None);
|
|
/// assert_eq!(pq.replace(3i), Some(1i));
|
|
/// assert_eq!(pq.len(), 1);
|
|
/// assert_eq!(pq.top(), Some(&3i));
|
|
/// ```
|
|
pub fn replace(&mut self, mut item: T) -> Option<T> {
|
|
if !self.is_empty() {
|
|
swap(&mut item, self.data.get_mut(0));
|
|
self.siftdown(0);
|
|
Some(item)
|
|
} else {
|
|
self.push(item);
|
|
None
|
|
}
|
|
}
|
|
|
|
#[allow(dead_code)]
|
|
#[deprecated="renamed to `into_vec`"]
|
|
fn to_vec(self) -> Vec<T> { self.into_vec() }
|
|
|
|
#[allow(dead_code)]
|
|
#[deprecated="renamed to `into_sorted_vec`"]
|
|
fn to_sorted_vec(self) -> Vec<T> { self.into_sorted_vec() }
|
|
|
|
/// Consumes the `PriorityQueue` and returns the underlying vector
|
|
/// in arbitrary order.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let pq = PriorityQueue::from_vec(vec![1i, 2, 3, 4, 5, 6, 7]);
|
|
/// let vec = pq.into_vec();
|
|
///
|
|
/// // Will print in some order
|
|
/// for x in vec.iter() {
|
|
/// println!("{}", x);
|
|
/// }
|
|
/// ```
|
|
pub fn into_vec(self) -> Vec<T> { let PriorityQueue{data: v} = self; v }
|
|
|
|
/// Consumes the `PriorityQueue` and returns a vector in sorted
|
|
/// (ascending) order.
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use std::collections::PriorityQueue;
|
|
///
|
|
/// let mut pq = PriorityQueue::from_vec(vec![1i, 2, 4, 5, 7]);
|
|
/// pq.push(6);
|
|
/// pq.push(3);
|
|
///
|
|
/// let vec = pq.into_sorted_vec();
|
|
/// assert_eq!(vec, vec![1i, 2, 3, 4, 5, 6, 7]);
|
|
/// ```
|
|
pub fn into_sorted_vec(self) -> Vec<T> {
|
|
let mut q = self;
|
|
let mut end = q.len();
|
|
while end > 1 {
|
|
end -= 1;
|
|
q.data.as_mut_slice().swap(0, end);
|
|
q.siftdown_range(0, end)
|
|
}
|
|
q.into_vec()
|
|
}
|
|
|
|
// The implementations of siftup and siftdown use unsafe blocks in
|
|
// order to move an element out of the vector (leaving behind a
|
|
// zeroed element), shift along the others and move it back into the
|
|
// vector over the junk element. This reduces the constant factor
|
|
// compared to using swaps, which involves twice as many moves.
|
|
fn siftup(&mut self, start: uint, mut pos: uint) {
|
|
unsafe {
|
|
let new = replace(self.data.get_mut(pos), zeroed());
|
|
|
|
while pos > start {
|
|
let parent = (pos - 1) >> 1;
|
|
if new > self.data[parent] {
|
|
let x = replace(self.data.get_mut(parent), zeroed());
|
|
ptr::write(self.data.get_mut(pos), x);
|
|
pos = parent;
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
ptr::write(self.data.get_mut(pos), new);
|
|
}
|
|
}
|
|
|
|
fn siftdown_range(&mut self, mut pos: uint, end: uint) {
|
|
unsafe {
|
|
let start = pos;
|
|
let new = replace(self.data.get_mut(pos), zeroed());
|
|
|
|
let mut child = 2 * pos + 1;
|
|
while child < end {
|
|
let right = child + 1;
|
|
if right < end && !(self.data[child] > self.data[right]) {
|
|
child = right;
|
|
}
|
|
let x = replace(self.data.get_mut(child), zeroed());
|
|
ptr::write(self.data.get_mut(pos), x);
|
|
pos = child;
|
|
child = 2 * pos + 1;
|
|
}
|
|
|
|
ptr::write(self.data.get_mut(pos), new);
|
|
self.siftup(start, pos);
|
|
}
|
|
}
|
|
|
|
fn siftdown(&mut self, pos: uint) {
|
|
let len = self.len();
|
|
self.siftdown_range(pos, len);
|
|
}
|
|
}
|
|
|
|
/// `PriorityQueue` iterator.
|
|
pub struct Items <'a, T:'a> {
|
|
iter: slice::Items<'a, T>,
|
|
}
|
|
|
|
impl<'a, T> Iterator<&'a T> for Items<'a, T> {
|
|
#[inline]
|
|
fn next(&mut self) -> Option<(&'a T)> { self.iter.next() }
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
|
|
}
|
|
|
|
impl<T: Ord> FromIterator<T> for PriorityQueue<T> {
|
|
fn from_iter<Iter: Iterator<T>>(mut iter: Iter) -> PriorityQueue<T> {
|
|
let vec: Vec<T> = iter.collect();
|
|
PriorityQueue::from_vec(vec)
|
|
}
|
|
}
|
|
|
|
impl<T: Ord> Extendable<T> for PriorityQueue<T> {
|
|
fn extend<Iter: Iterator<T>>(&mut self, mut iter: Iter) {
|
|
let (lower, _) = iter.size_hint();
|
|
|
|
let len = self.capacity();
|
|
self.reserve(len + lower);
|
|
|
|
for elem in iter {
|
|
self.push(elem);
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use std::prelude::*;
|
|
|
|
use priority_queue::PriorityQueue;
|
|
use vec::Vec;
|
|
use MutableSeq;
|
|
|
|
#[test]
|
|
fn test_iterator() {
|
|
let data = vec!(5i, 9, 3);
|
|
let iterout = [9i, 5, 3];
|
|
let pq = PriorityQueue::from_vec(data);
|
|
let mut i = 0;
|
|
for el in pq.iter() {
|
|
assert_eq!(*el, iterout[i]);
|
|
i += 1;
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn test_top_and_pop() {
|
|
let data = vec!(2u, 4, 6, 2, 1, 8, 10, 3, 5, 7, 0, 9, 1);
|
|
let mut sorted = data.clone();
|
|
sorted.sort();
|
|
let mut heap = PriorityQueue::from_vec(data);
|
|
while !heap.is_empty() {
|
|
assert_eq!(heap.top().unwrap(), sorted.last().unwrap());
|
|
assert_eq!(heap.pop().unwrap(), sorted.pop().unwrap());
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn test_push() {
|
|
let mut heap = PriorityQueue::from_vec(vec!(2i, 4, 9));
|
|
assert_eq!(heap.len(), 3);
|
|
assert!(*heap.top().unwrap() == 9);
|
|
heap.push(11);
|
|
assert_eq!(heap.len(), 4);
|
|
assert!(*heap.top().unwrap() == 11);
|
|
heap.push(5);
|
|
assert_eq!(heap.len(), 5);
|
|
assert!(*heap.top().unwrap() == 11);
|
|
heap.push(27);
|
|
assert_eq!(heap.len(), 6);
|
|
assert!(*heap.top().unwrap() == 27);
|
|
heap.push(3);
|
|
assert_eq!(heap.len(), 7);
|
|
assert!(*heap.top().unwrap() == 27);
|
|
heap.push(103);
|
|
assert_eq!(heap.len(), 8);
|
|
assert!(*heap.top().unwrap() == 103);
|
|
}
|
|
|
|
#[test]
|
|
fn test_push_unique() {
|
|
let mut heap = PriorityQueue::from_vec(vec!(box 2i, box 4, box 9));
|
|
assert_eq!(heap.len(), 3);
|
|
assert!(*heap.top().unwrap() == box 9);
|
|
heap.push(box 11);
|
|
assert_eq!(heap.len(), 4);
|
|
assert!(*heap.top().unwrap() == box 11);
|
|
heap.push(box 5);
|
|
assert_eq!(heap.len(), 5);
|
|
assert!(*heap.top().unwrap() == box 11);
|
|
heap.push(box 27);
|
|
assert_eq!(heap.len(), 6);
|
|
assert!(*heap.top().unwrap() == box 27);
|
|
heap.push(box 3);
|
|
assert_eq!(heap.len(), 7);
|
|
assert!(*heap.top().unwrap() == box 27);
|
|
heap.push(box 103);
|
|
assert_eq!(heap.len(), 8);
|
|
assert!(*heap.top().unwrap() == box 103);
|
|
}
|
|
|
|
#[test]
|
|
fn test_push_pop() {
|
|
let mut heap = PriorityQueue::from_vec(vec!(5i, 5, 2, 1, 3));
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.push_pop(6), 6);
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.push_pop(0), 5);
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.push_pop(4), 5);
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.push_pop(1), 4);
|
|
assert_eq!(heap.len(), 5);
|
|
}
|
|
|
|
#[test]
|
|
fn test_replace() {
|
|
let mut heap = PriorityQueue::from_vec(vec!(5i, 5, 2, 1, 3));
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.replace(6).unwrap(), 5);
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.replace(0).unwrap(), 6);
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.replace(4).unwrap(), 5);
|
|
assert_eq!(heap.len(), 5);
|
|
assert_eq!(heap.replace(1).unwrap(), 4);
|
|
assert_eq!(heap.len(), 5);
|
|
}
|
|
|
|
fn check_to_vec(mut data: Vec<int>) {
|
|
let heap = PriorityQueue::from_vec(data.clone());
|
|
let mut v = heap.clone().into_vec();
|
|
v.sort();
|
|
data.sort();
|
|
|
|
assert_eq!(v.as_slice(), data.as_slice());
|
|
assert_eq!(heap.into_sorted_vec().as_slice(), data.as_slice());
|
|
}
|
|
|
|
#[test]
|
|
fn test_to_vec() {
|
|
check_to_vec(vec!());
|
|
check_to_vec(vec!(5i));
|
|
check_to_vec(vec!(3i, 2));
|
|
check_to_vec(vec!(2i, 3));
|
|
check_to_vec(vec!(5i, 1, 2));
|
|
check_to_vec(vec!(1i, 100, 2, 3));
|
|
check_to_vec(vec!(1i, 3, 5, 7, 9, 2, 4, 6, 8, 0));
|
|
check_to_vec(vec!(2i, 4, 6, 2, 1, 8, 10, 3, 5, 7, 0, 9, 1));
|
|
check_to_vec(vec!(9i, 11, 9, 9, 9, 9, 11, 2, 3, 4, 11, 9, 0, 0, 0, 0));
|
|
check_to_vec(vec!(0i, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
|
|
check_to_vec(vec!(10i, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0));
|
|
check_to_vec(vec!(0i, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 1, 2));
|
|
check_to_vec(vec!(5i, 4, 3, 2, 1, 5, 4, 3, 2, 1, 5, 4, 3, 2, 1));
|
|
}
|
|
|
|
#[test]
|
|
fn test_empty_pop() {
|
|
let mut heap: PriorityQueue<int> = PriorityQueue::new();
|
|
assert!(heap.pop().is_none());
|
|
}
|
|
|
|
#[test]
|
|
fn test_empty_top() {
|
|
let empty: PriorityQueue<int> = PriorityQueue::new();
|
|
assert!(empty.top().is_none());
|
|
}
|
|
|
|
#[test]
|
|
fn test_empty_replace() {
|
|
let mut heap: PriorityQueue<int> = PriorityQueue::new();
|
|
heap.replace(5).is_none();
|
|
}
|
|
|
|
#[test]
|
|
fn test_from_iter() {
|
|
let xs = vec!(9u, 8, 7, 6, 5, 4, 3, 2, 1);
|
|
|
|
let mut q: PriorityQueue<uint> = xs.as_slice().iter().rev().map(|&x| x).collect();
|
|
|
|
for &x in xs.iter() {
|
|
assert_eq!(q.pop().unwrap(), x);
|
|
}
|
|
}
|
|
}
|