Init repo

Author: davidnguyen11

.gitignore

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+node_modules

dist/heap.js

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+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+class Heap {
+    constructor(array = [], comparator, swapper) {
+        this.array = array;
+        this.pivot = Math.floor(this.array.length / 2);
+        this.comparator = comparator;
+        this.swapper = swapper;
+    }
+    build() {
+        for (let i = this.pivot - 1; i >= 0; i--) {
+            this.heapify(i);
+        }
+    }
+    heapify(index) {
+        let childIndex1;
+        let childIndex2;
+        while (index <= this.pivot - 1) {
+            childIndex1 = 2 * index + 1;
+            childIndex2 = 2 * index + 2;
+            let swapIndex = childIndex1;
+            if (this.compare(this.array[childIndex1], this.array[childIndex2])) {
+                swapIndex = childIndex2;
+            }
+            if (this.compare(this.array[index], this.array[swapIndex])) {
+                this.swap(index, swapIndex);
+            }
+            index = swapIndex;
+        }
+    }
+    swap(index1, index2) {
+        if (this.swapper) {
+            this.swapper(index1, index2);
+        }
+        else {
+            const temp = this.array[index1];
+            this.array[index1] = this.array[index2];
+            this.array[index2] = temp;
+        }
+    }
+    compare(item1, item2) {
+        if (this.comparator) {
+            return this.comparator(item1, item2);
+        }
+        return item1 < item2;
+    }
+}
+exports.Heap = Heap;

dist/index.js

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+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const heap_1 = require("./heap");
+const h = new heap_1.Heap([2, 7, 4, 1, 8, 1]);
+h.build();
+console.log(h.array);

dist/interface.js

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+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+;

dist/priority-queue.js

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+{
+  "name": "priority-queue",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "build": "tsc",
+    "test": "node ./dist/index"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "typescript": "^3.8.3"
+  }
+}

package-lock.json

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+import { IHeap } from './interface';
+
+export class Heap<T> implements IHeap {
+  public array: T[];
+  private pivot: number;
+  private comparator: (item1: T, item2: T) => boolean;
+  private swapper: (index1: number, index2: number) => void;
+
+  constructor(
+    array: T[] = [],
+    comparator?: (item1: T, item2: T) => boolean,
+    swapper?: (index1: number, index2: number) => void
+  ) {
+    this.array = array;
+    this.pivot = Math.floor(this.array.length / 2);
+    this.comparator = comparator;
+    this.swapper = swapper;
+  }
+
+  public build() {
+    for (let i = this.pivot - 1; i >= 0; i--) {
+      this.heapify(i);
+    }
+  }
+
+  public heapify(index: number) {
+    let childIndex1;
+    let childIndex2;
+
+    while (index <= this.pivot - 1) {
+      childIndex1 = 2 * index + 1;
+      childIndex2 = 2 * index + 2;
+      let swapIndex = childIndex1;
+
+      if (this.compare(this.array[childIndex1], this.array[childIndex2])) {
+        swapIndex = childIndex2;
+      }
+
+      if (this.compare(this.array[index], this.array[swapIndex])) {
+        this.swap(index, swapIndex);
+      }
+
+      index = swapIndex;
+    }
+  }
+
+  public swap(index1: number, index2: number) {
+    if (this.swapper) {
+      this.swapper(index1, index2);
+    } else {
+      const temp = this.array[index1];
+      this.array[index1] = this.array[index2];
+      this.array[index2] = temp;
+    }
+  }
+
+  private compare(item1: T, item2: T) {
+    if (this.comparator) {
+      return this.comparator(item1, item2);
+    }
+    return item1 < item2;
+  }
+}

package.json

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+import { Heap } from './heap';
+
+const h = new Heap([2, 7, 4, 1, 8, 1]);
+h.build();
+
+console.log(h.array);
+
+
+// var stones = [2, 7, 4, 1, 8, 1];
+// var stones = [4, 3, 4, 3, 2];
+// var stones = [722, 512, 290, 559, 884, 608, 932, 781, 864, 398, 890, 574, 472, 125, 620, 728, 447, 150, 52, 116, 786, 717, 172, 549, 350, 268, 951, 315, 482, 170];

src/heap.ts

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+export interface IHeap {
+  build: () => void;
+  heapify: (index: number) => void;
+};
+
+export interface IPriorityQueue<T> {
+  add?: (e: T) => void;
+  peek?: () => void;
+  poll?: () => void;
+  remove?: () => void;
+  contains?: () => void;
+  size?: () => void;
+  clear?: () => void;
+}