Merge pull request #55 from datastructures-js/add_remove

add remove method

Author: eyas-ranjous

CHANGELOG.md

@@ -5,6 +5,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+## [6.3.0] - 2023-05-30
+### Added
+- `.remove(cb)` to remove all elements that meet a criteria.
+
 ## [6.2.0] - 2023-01-16
 ### Added
 - Symbol.iterator

README.md

@@ -18,6 +18,7 @@ A heap-based implementation of priority queue in javascript with typescript supp
   * [front](#front)
   * [back](#back)
   * [dequeue (pop)](#dequeue-pop)
+  * [remove](#remove)
   * [isEmpty](#isEmpty)
   * [size](#size)
   * [toArray](#toarray)
@@ -242,6 +243,17 @@ console.log(bidsQueue.pop()); // { id: 5, value: 12000 }
 console.log(bidsQueue.pop()); // { id: 7, value: 8000 }
 ```
 
+### remove
+removes all elements that meet a criteria in O(n*log(n)) runtime and return a list of the removed elements.
+
+```js
+carsQueue.remove((car) => car.price === 35000); // [{ year: 2013, price: 35000 }]
+
+numbersQueue.remove((n) => n === 4); // [4]
+
+bidsQueue.remove((bid) => bid.id === 3); // [{ id: 3, value: 1000 }]
+```
+
 ### isEmpty
 checks if the queue is empty.
 
@@ -255,9 +267,9 @@ console.log(bidsQueue.isEmpty()); // false
 returns the number of elements in the queue.
 
 ```js
-console.log(carsQueue.size()); // 4
-console.log(numbersQueue.size()); // 4
-console.log(bidsQueue.size()); // 4
+console.log(carsQueue.size()); // 3
+console.log(numbersQueue.size()); // 3
+console.log(bidsQueue.size()); // 3
 ```
 
 ### toArray
@@ -269,19 +281,17 @@ console.log(carsQueue.toArray());
 [
   { year: 2013, price: 25000 },
   { year: 2013, price: 30000 },
-  { year: 2013, price: 35000 },
   { year: 2010, price: 2000 }
 ]
 */
 
-console.log(numbersQueue.toArray()); // [ 0, 3, 4, 5 ]
+console.log(numbersQueue.toArray()); // [ 0, 3, 5 ]
 
 console.log(bidsQueue.toArray());
 /*
 [
   { id: 6, value: 4000 },
   { id: 4, value: 1500 },
-  { id: 3, value: 1000 },
   { id: 1, value: 1000 }
 ]
 */
@@ -295,13 +305,12 @@ console.log([...carsQueue]);
 [
   { year: 2013, price: 25000 },
   { year: 2013, price: 30000 },
-  { year: 2013, price: 35000 },
   { year: 2010, price: 2000 }
 ]
 */
 console.log(carsQueue.size()); // 0
 
-console.log([...numbersQueue]); // [ 0, 3, 4, 5 ]
+console.log([...numbersQueue]); // [ 0, 3, 5 ]
 console.log(numbersQueue.size()); // 0
 
 for (const bid of bidsQueue) {
@@ -310,7 +319,6 @@ for (const bid of bidsQueue) {
 /*
 { id: 6, value: 4000 },
 { id: 4, value: 1500 },
-{ id: 3, value: 1000 },
 { id: 1, value: 1000 }
 */
 console.log(bidsHeap.size()); // 0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@datastructures-js/priority-queue",
-  "version": "6.2.0",
+  "version": "6.3.0",
   "description": "A heap-based implementation of priority queue in javascript with typescript support.",
   "main": "index.js",
   "types": "index.d.ts",

src/maxPriorityQueue.d.ts

@@ -11,6 +11,7 @@ export class MaxPriorityQueue<T> {
   push(value: T): MaxPriorityQueue<T>;
   dequeue(): T;
   pop(): T;
+  remove(cb: (value: T) => boolean): T[];
   toArray(): T[];
   clear(): void;
   static fromArray<T>(values: T[], getCompareValue?: IGetCompareValue<T>): MaxPriorityQueue<T>;

src/maxPriorityQueue.js

@@ -79,6 +79,32 @@ class MaxPriorityQueue {
     return this.dequeue();
   }
 
+  /**
+   * Removes all elements that match a criteria in the callback
+   * @public
+   * @param {function} cb
+   * @returns {array}
+   */
+  remove(cb) {
+    if (typeof cb !== 'function') {
+      throw new Error('MaxPriorityQueue remove expects a callback');
+    }
+
+    const removed = [];
+    const dequeued = [];
+    while (!this.isEmpty()) {
+      const popped = this.pop();
+      if (cb(popped)) {
+        removed.push(popped);
+      } else {
+        dequeued.push(popped);
+      }
+    }
+
+    dequeued.forEach((val) => this.push(val));
+    return removed;
+  }
+
   /**
    * Returns the number of elements in the queue
    * @public

src/minPriorityQueue.d.ts

@@ -11,6 +11,7 @@ export class MinPriorityQueue<T> {
   push(value: T): MinPriorityQueue<T>;
   dequeue(): T;
   pop(): T;
+  remove(cb: (value: T) => boolean): T[];
   toArray(): T[];
   clear(): void;
   static fromArray<T>(values: T[], getCompareValue?: IGetCompareValue<T>): MinPriorityQueue<T>;

src/minPriorityQueue.js

@@ -78,6 +78,32 @@ class MinPriorityQueue {
     return this.dequeue();
   }
 
+  /**
+   * Removes all elements that match a criteria in the callback
+   * @public
+   * @param {function} cb
+   * @returns {array}
+   */
+  remove(cb) {
+    if (typeof cb !== 'function') {
+      throw new Error('MinPriorityQueue remove expects a callback');
+    }
+
+    const removed = [];
+    const dequeued = [];
+    while (!this.isEmpty()) {
+      const popped = this.pop();
+      if (cb(popped)) {
+        removed.push(popped);
+      } else {
+        dequeued.push(popped);
+      }
+    }
+
+    dequeued.forEach((val) => this.push(val));
+    return removed;
+  }
+
   /**
    * Returns the number of elements in the queue
    * @public

src/priorityQueue.d.ts

@@ -11,6 +11,7 @@ export class PriorityQueue<T> {
   push(value: T): PriorityQueue<T>;
   dequeue(): T;
   pop(): T;
+  remove(cb: (value: T) => boolean): T[];
   toArray(): T[];
   clear(): void;
   static fromArray<T>(values: T[], compare: ICompare<T>): PriorityQueue<T>;

src/priorityQueue.js

@@ -79,6 +79,32 @@ class PriorityQueue {
     return this.dequeue();
   }
 
+  /**
+   * Removes all elements that match a criteria in the callback
+   * @public
+   * @param {function} cb
+   * @returns {array}
+   */
+  remove(cb) {
+    if (typeof cb !== 'function') {
+      throw new Error('PriorityQueue remove expects a callback');
+    }
+
+    const removed = [];
+    const dequeued = [];
+    while (!this.isEmpty()) {
+      const popped = this.pop();
+      if (cb(popped)) {
+        removed.push(popped);
+      } else {
+        dequeued.push(popped);
+      }
+    }
+
+    dequeued.forEach((val) => this.push(val));
+    return removed;
+  }
+
   /**
    * Returns the number of elements in the queue
    * @public

test/PriorityQueue.test.js

@@ -108,6 +108,18 @@ describe('PriorityQueue', () => {
     });
   });
 
+  describe('remove', () => {
+    it('remove elements that match a criteria', () => {
+      const testArr = [20, 30, 40, 50, 80, 90];
+      const qTest = PriorityQueue.fromArray(testArr.slice(), (a, b) => a - b);
+      const removed = qTest.remove((n) => [30, 50, 80].includes(n));
+      expect(removed.sort()).to.eql([30, 50, 80]);
+      expect(qTest.pop()).to.eql(20);
+      expect(qTest.pop()).to.eql(40);
+      expect(qTest.pop()).to.eql(90);
+    });
+  });
+
   describe('iterator', () => {
     it('allows iterating on queue elements', () => {
       const testArr = [20, 30, 40, 50, 80, 90];