What

Brief

This is a standalone Priority Queue data structure from the data-structure-typed collection. If you wish to access more data structures or advanced features, you can transition to directly installing the complete data-structure-typed package

How

install

npm

npm i priority-queue-typed --save

yarn

yarn add priority-queue-typed

snippet

TS

    import {PriorityQueue, MinPriorityQueue} from 'data-structure-typed';
    // /* or if you prefer */ import {PriorityQueue, MinPriorityQueue} from 'priority-queue-typed';

    const minPQ = new PriorityQueue<number>({nodes: [5, 2, 3, 4, 6, 1], comparator: (a, b) => a - b});
    minPQ.toArray()             //  [1, 2, 3, 4, 6, 5]
    minPQ.poll();
    minPQ.poll();
    minPQ.poll();
    minPQ.toArray()             //  [4, 5, 6]
    minPQ.peek()                //  4
    PriorityQueue.heapify({
        nodes: [3, 2, 1, 5, 6, 7, 8, 9, 10],
        comparator: (a, b) => a - b
    }).toArray()                //  [1, 2, 3, 5, 6, 7, 8, 9, 10]

    const priorityQueue = new MinPriorityQueue<number>();
    priorityQueue.add(5);
    priorityQueue.add(3);
    priorityQueue.add(7);
    priorityQueue.add(1);
    const sortedArray = priorityQueue.sort(); //  [1, 3, 5, 7]);

    const minPQ1 = new PriorityQueue<number>({nodes: [2, 5, 8, 3, 1, 6, 7, 4], comparator: (a, b) => a - b});
    const clonedPriorityQueue = minPQ1.clone();
    clonedPriorityQueue.getNodes()  //  minPQ1.getNodes()
    clonedPriorityQueue.sort()      //  [1, 2, 3, 4, 5, 6, 7, 8]
    minPQ1.DFS('in')                //  [4, 3, 2, 5, 1, 8, 6, 7]
    minPQ1.DFS('post')              //  [4, 3, 5, 2, 8, 7, 6, 1]
    minPQ1.DFS('pre')               //  [1, 2, 3, 4, 5, 6, 8, 7]

JS

    const {PriorityQueue, MinPriorityQueue} = require('data-structure-typed');
    // /* or if you prefer */ const {PriorityQueue, MinPriorityQueue} = require('priority-queue-typed');

    const minPQ = new PriorityQueue({nodes: [5, 2, 3, 4, 6, 1], comparator: (a, b) => a - b});
    minPQ.toArray()             //  [1, 2, 3, 4, 6, 5]
    minPQ.poll();
    minPQ.poll();
    minPQ.poll();
    minPQ.toArray()             //  [4, 5, 6]
    minPQ.peek()                //  4
    PriorityQueue.heapify({
        nodes: [3, 2, 1, 5, 6, 7, 8, 9, 10],
        comparator: (a, b) => a - b
    }).toArray()                //  [1, 2, 3, 5, 6, 7, 8, 9, 10]
    
    const priorityQueue = new MinPriorityQueue();
    priorityQueue.add(5);
    priorityQueue.add(3);
    priorityQueue.add(7);
    priorityQueue.add(1);
    const sortedArray = priorityQueue.sort(); //  [1, 3, 5, 7]);
    
    const minPQ1 = new PriorityQueue<number>({nodes: [2, 5, 8, 3, 1, 6, 7, 4], comparator: (a, b) => a - b});
    const clonedPriorityQueue = minPQ1.clone();
    clonedPriorityQueue.getNodes()  //  minPQ1.getNodes()
    clonedPriorityQueue.sort()      //  [1, 2, 3, 4, 5, 6, 7, 8]
    minPQ1.DFS('in')                //  [4, 3, 2, 5, 1, 8, 6, 7]
    minPQ1.DFS('post')              //  [4, 3, 5, 2, 8, 7, 6, 1]
    minPQ1.DFS('pre')               //  [1, 2, 3, 4, 5, 6, 8, 7]

Hospital emergency room triage

 interface Patient {
      name: string;
      severity: number; // 1 = critical, 5 = minor
    }

    const er = new PriorityQueue<Patient>([], {
      comparator: (a, b) => a.severity - b.severity
    });

    er.add({ name: 'Flu symptoms', severity: 4 });
    er.add({ name: 'Heart attack', severity: 1 });
    er.add({ name: 'Broken arm', severity: 3 });
    er.add({ name: 'Stroke', severity: 1 });

    // Most critical patients first
    console.log(er.poll()?.severity); // 1;
    console.log(er.poll()?.severity); // 1;
    console.log(er.poll()?.severity); // 3;
    console.log(er.poll()?.severity); // 4;

Task scheduler with deadlines

 interface Task {
      name: string;
      deadline: number; // hours until due
    }

    const scheduler = new PriorityQueue<Task>([], {
      comparator: (a, b) => a.deadline - b.deadline
    });

    scheduler.add({ name: 'Report', deadline: 24 });
    scheduler.add({ name: 'Email', deadline: 2 });
    scheduler.add({ name: 'Meeting prep', deadline: 4 });
    scheduler.add({ name: 'Code review', deadline: 8 });

    // Process most urgent first
    console.log(scheduler.peek()?.name); // 'Email';
    console.log(scheduler.size); // 4;

    const order = [];
    while (scheduler.size > 0) {
      order.push(scheduler.poll()!.name);
    }
    console.log(order); // ['Email', 'Meeting prep', 'Code review', 'Report'];

Bandwidth allocation with priorities

 const bandwidth = new PriorityQueue<[number, string]>([], {
      comparator: (a, b) => a[0] - b[0]
    });

    bandwidth.add([1, 'Video call']);     // highest priority
    bandwidth.add([3, 'File download']);
    bandwidth.add([2, 'Web browsing']);
    bandwidth.add([1, 'Voice call']);

    // Allocate bandwidth to highest priority first
    console.log(bandwidth.poll()?.[1]); // 'Video call';
    console.log(bandwidth.poll()?.[1]); // 'Voice call';
    console.log(bandwidth.size); // 2;

API docs & Examples

API Docs

Live Examples

Examples Repository

Data Structures

Standard library data structure comparison

Benchmark

Built-in classic algorithms

Software Engineering Design Standards