Min Priority Queue in TypeScript

/**

* @class

* Class representing a min/max PriorityQueue

*

* The default is a minPriorityQueue if no value is used in the constructor.

* If you want a maxPriorityQueue, pass true in the constructor e.g.

*

* let maxPQ = new PriorityQueue(true);

* let minPQ = new PriorityQueue();

*

* AppsScripts won't let you define private methods, so here are the public methds

*

* add(v {int}) // adds a new value into the queue

* contains(v {int}) // returns true if the queue contains the value

* isEmpty() {bool} // returns true if there are no ints in the queue

* pop() {int} // returns the min/max value in the queue

*

*/

class PriorityQueue {

constructor(isMax) {

if (undefined == isMax || null == isMax || false == isMax) {

this.isMax = false;

} else {

this.isMax = true;

}

this.heap = [];

this.index = new Map();

this.size = this.heap.length;

}

contains(v) {

return this.index.has(v);

}

exch(i, j) {

let t = this.heap[i];

this.heap[i] = this.heap[j];

this.index.set(t, j);

this.index.set(this.heap[j], i);

this.heap[j] = t;

}

add(v) {

if (this.contains(v)) return;

this.size++;

this.heap[this.size] = v;

this.swim(this.size);

this.index.set(v, this.size);

}

isEmpty() {

return this.size == 0;

}

length() {

return this.size;

}

less(i, j) {

if (this.isMax) {

return this.heap[i] < this.heap[j];

}

return this.heap[i] > this.heap[j];

}

pop() {

let max = this.heap[1];

this.exch(1, this.size--);

this.heap.pop();

this.sink(1);

return max;

}

sink(n) {

while (n*2 <= this.size) {

let j = n*2;

if (j < this.size && this.less(j, j+1)) j++;

if (!this.less(n, j)) break;

this.exch(n, j);

n = j;

}

}

swim(n) {

while (n > 1 && this.less(Math.floor(n/2), n)) {

this.exch(Math.floor(n/2), n);

n = Math.floor(n/2);

}

}

}

function testArray() {

console.log("Testing a min PQ.");

let t = new PriorityQueue(false);

console.log("Inserting 7, 5, 9, 3, 10, 1");

t.add(7);

t.add(5);

t.add(9);

t.add(7);

t.add(3);

t.add(10);

t.add(1);

console.log(`Does the queue contain 5? : ${t.contains(5)}`);

console.log(`Does the queue contain 3? : ${t.contains(3)}`);

let incr = 0;

let output = "";

while (!t.isEmpty() && incr++ < 10)

output += `${t.pop()} `;

console.log(`Output: ${output}`);

console.log("Testing a max PQ.");

console.log("Inserting 7, 5, 9, 3, 10, 1");

output = "";

t = new PriorityQueue(true);

t.add(7);

t.add(5);

t.add(9);

t.add(3);

t.add(10);

t.add(1);

console.log(`Does the queue contain 5? : ${t.contains(5)}`);

console.log(`Does the queue contain 3? : ${t.contains(3)}`);

incr = 0;

while (!t.isEmpty() && incr++ < 10)

output += `${t.pop()} `;

console.log(`Output: ${output}`);

}