done!

.gitignore

@@ -102,6 +102,3 @@ dist
 
 # TernJS port file
 .tern-port
-
-
-yarn.lock

README.md

@@ -1,7 +1,32 @@
 # priority-queue
-Priority queue(优先队列) implementation in JavaScript
+> Priority queue(优先队列) implementation in JavaScript
 
 > 学习项目，参考自：[mourner/tinyqueue](https://github.com/mourner/tinyqueue)
 
+## install
+```sh
+npm i @kartjim/priority-queue
+```
 
+## import
+```js
+import PriorityQueue from '@kartjim/priority-queue';
+```
+
+or use CDN:
+```js
+<script src="https://cdn.jsdelivr.net/npm/@kartjim/[email protected]/priorityqueue.min.js"></script>
+```
+
+## API
+- constructor
+  - `constructor(data?: T[],compare?: (a: T, b: T) => number);`
+- `push(val: T) : void;`
+  - push an element into PriorityQueue
+- `peek() : T | undefined;`
+  - get the top element
+- `pop() : T | undefined;`
+  - pop an element, and return it
+- `isEmpty() : boolean;`
+  - check if the PriorityQueue is empty
 

__test__/bench.js

@@ -0,0 +1,24 @@
+import PriorityQueue from '../index.js';
+
+const NUM = 1e5;
+
+const data = [];
+for (let i = 0; i < NUM; i++) {
+    data.push({
+        value: Math.random()
+    });
+}
+
+const heap = new PriorityQueue(data, (a, b) => a.value - b.value);
+
+console.time(`push ${NUM}`);
+for (let i = 0; i < NUM; i++) {
+    heap.push(data[i]);
+}
+console.timeEnd(`push ${NUM}`); // push 100000: 47.846ms
+
+console.time(`pop ${NUM}`);
+for (let i = 0; i < NUM; i++) {
+    heap.pop();
+}
+console.timeEnd(`pop ${NUM}`); // pop 100000: 153.495ms

__test__/test.js

@@ -0,0 +1,55 @@
+import {test} from 'tape';
+import PriorityQueue from '../index.js';
+
+// create data
+const data = [];
+for (let i = 0; i < 50; i++) {
+    data.push(~~(50 * Math.random()));
+}
+
+const sorted = data.slice().sort((a, b) => a - b);
+
+test('maintains a default params PriorityQueue', (t) => {
+    const heap = new PriorityQueue();
+    for (let i = 0; i < data.length; i++) {
+        heap.push(data[i]);
+    }
+
+    t.equal(heap.peek(), sorted[0]);
+
+    let ans = [];
+    while (!heap.isEmpty()) {
+        ans.push(heap.pop());
+    }
+
+    t.deepEqual(ans, sorted);
+    // console.log(ans);
+
+    t.end();
+});
+
+test('get data from constructor', (t) => {
+    const heap = new PriorityQueue(data.slice());
+
+    let ans = [];
+    while (!heap.isEmpty()) {
+        ans.push(heap.pop());
+    }
+
+    t.deepEqual(ans, sorted);
+
+    t.end();
+});
+
+test('push and pop some elements', (t) => {
+    const heap = new PriorityQueue();
+
+    t.same(heap.data, []);
+    heap.push(3);
+    heap.push(2);
+    t.equal(heap.pop(), 2);
+    t.equal(heap.pop(), 3);
+    t.equal(heap.pop(), undefined);
+
+    t.end();
+});

index.js

@@ -9,7 +9,7 @@ export default class PriorityQueue {
     constructor(
         data = [],
         compare = function (a, b) {
-            return a === b ? 0 : a > b ? 1 : -1;
+            return a > b ? 1 : a < b ? -1 : 0;
         }
     ) {
         this.data = data;
@@ -51,21 +51,22 @@ export default class PriorityQueue {
         if (this.isEmpty()) return undefined;
 
         const top = this.data[0];
+        const bottom = this.data.pop();
+
         this.size--;
-        if (this.isEmpty()) {
-            return this.data.pop();
+        if (!this.isEmpty()) {
+            this.data[0] = bottom;
+            this._up(0);
         }
-        this.data[0] = this.data.pop();
-        this._up(0);
         return top;
     }
 
     _up(pos) {
         let half = Math.floor(this.size / 2);
         let val = this.data[pos];
         while (pos < half) {
-            let more = pos * 2 + 1;
-            let right = more + 2;
+            let more =  (pos << 1) + 1;
+            let right = more + 1;
             if (right < this.size && this.compare(this.data[right], this.data[more]) < 0) {
                 more = right;
             }

package.json

@@ -8,13 +8,11 @@
   "unpkg": "priorityqueue.min.js",
   "types": "index.d.ts",
   "scripts": {
-    "lint": "eslint index.js",
-    "pretest": "npm run lint",
-    "test": "tape -r esm test.js",
-    "bench": "node -r esm bench.js",
+    "lint": "eslint index.js __test__/test.js __test__/bench.js",
+    "test": "tape -r esm __test__/test.js",
+    "bench": "node -r esm __test__/bench.js",
     "build": "rollup -c",
-    "watch": "rollup -cw",
-    "prepublishOnly": "npm test"
+    "watch": "rollup -cw"
   },
   "files": [
     "index.js",