Keyed Priority Queue

A Rust library with priority queue that supports changing of priority item in queue or early removal. To change priority you need to use some key.

Usage

Add this to your Cargo.toml: toml [dependencies] keyed_priority_queue = "0.1.0"

The example of code:

```rust use keyedpriorityqueue::KeyedPriorityQueue;

let mut queue = KeyedPriorityQueue::new();

// Currently queue is empty assert_eq!(queue.peek(), None);

queue.push("Second", 4); queue.push("Third", 3); queue.push("First", 5); queue.push("Fourth", 2); queue.push("Fifth", 1);

// Peek return references to most important pair. assert_eq!(queue.peek(), Some((&"First", &5)));

assert_eq!(queue.len(), 5);

// We can clone queue if both key and priority is clonable let mut queue_clone = queue.clone();

// We can run consuming iterator on queue, // and it will return items in decreasing order for (key, priority) in queue_clone{ println!("Priority of key {} is {}", key, priority); }

// Popping always will return the biggest element asserteq!(queue.pop(), Some(("First", 5))); // We can change priority of item by key: queue.setpriority(&"Fourth", 10); // And get it asserteq!(queue.getpriority(&"Fourth"), Some(&10)); // Now biggest element is Fourth asserteq!(queue.pop(), Some(("Fourth", 10))); // We can also decrease priority! queue.setpriority(&"Second", -1); asserteq!(queue.pop(), Some(("Third", 3))); asserteq!(queue.pop(), Some(("Fifth", 1))); asserteq!(queue.pop(), Some(("Second", -1))); // Now queue is empty asserteq!(queue.pop(), None);

// We can clear queue queue.clear(); assert!(queue.is_empty()); ```