const powerset = arr =>
  arr.reduce((a, v) => a.concat(a.map(r => r.concat(v))), [[]]);
  
powerset([1, 2]); // [[], [1], [2], [1, 2]]

class Graph {
  constructor(directed = true) {
    this.directed = directed;
    this.nodes = [];
    this.edges = new Map();
  }

  addNode(key, value = key) {
    this.nodes.push({ key, value });
  }

  addEdge(a, b, weight) {
    this.edges.set(JSON.stringify([a, b]), { a, b, weight });
    if (!this.directed)
      this.edges.set(JSON.stringify([b, a]), { a: b, b: a, weight });
  }

  removeNode(key) {
    this.nodes = this.nodes.filter(n => n.key !== key);
    [...this.edges.values()].forEach(({ a, b }) => {
      if (a === key || b === key) this.edges.delete(JSON.stringify([a, b]));
    });
  }

  removeEdge(a, b) {
    this.edges.delete(JSON.stringify([a, b]));
    if (!this.directed) this.edges.delete(JSON.stringify([b, a]));
  }

  findNode(key) {
    return this.nodes.find(x => x.key === key);
  }

  hasEdge(a, b) {
    return this.edges.has(JSON.stringify([a, b]));
  }

  setEdgeWeight(a, b, weight) {
    this.edges.set(JSON.stringify([a, b]), { a, b, weight });
    if (!this.directed)
      this.edges.set(JSON.stringify([b, a]), { a: b, b: a, weight });
  }

  getEdgeWeight(a, b) {
    return this.edges.get(JSON.stringify([a, b])).weight;
  }

  adjacent(key) {
    return [...this.edges.values()].reduce((acc, { a, b }) => {
      if (a === key) acc.push(b);
      return acc;
    }, []);
  }

  indegree(key) {
    return [...this.edges.values()].reduce((acc, { a, b }) => {
      if (b === key) acc++;
      return acc;
    }, 0);
  }

  outdegree(key) {
    return [...this.edges.values()].reduce((acc, { a, b }) => {
      if (a === key) acc++;
      return acc;
    }, 0);
  }
}


const g = new Graph();

g.addNode('a');
g.addNode('b');
g.addNode('c');
g.addNode('d');

g.addEdge('a', 'c');
g.addEdge('b', 'c');
g.addEdge('c', 'b');
g.addEdge('d', 'a');

g.nodes.map(x => x.value);  // ['a', 'b', 'c', 'd']
[...g.edges.values()].map(({ a, b }) => `${a} => ${b}`);
// ['a => c', 'b => c', 'c => b', 'd => a']

g.adjacent('c');            // ['b']

g.indegree('c');            // 2
g.outdegree('c');           // 1

g.hasEdge('d', 'a');        // true
g.hasEdge('a', 'd');        // false

g.removeEdge('c', 'b');

[...g.edges.values()].map(({ a, b }) => `${a} => ${b}`);
// ['a => c', 'b => c', 'd => a']

g.removeNode('c');

g.nodes.map(x => x.value);  // ['a', 'b', 'd']
[...g.edges.values()].map(({ a, b }) => `${a} => ${b}`);
// ['d => a']

g.setEdgeWeight('d', 'a', 5);
g.getEdgeWeight('d', 'a');  // 5

arr = [] // empty array
const isEmpty = arr => !Array.isArray(arr) || arr.length === 0;

// Examples
isEmpty([]); // true
isEmpty([1, 2, 3]); // false

questions = Array.from(document.querySelectorAll(".multiple-choice-question"));
async function hackRadio(question){
	if(question.querySelector(".question-chevron").getAttribute("aria-label") == "Question completed") return;
	let answerChoices = question.querySelectorAll(".zb-radio-button");
	async function guess(answerChoice){
		answerChoice.querySelector("label").click();
	}
	let pause = 0;
	for(let answerChoice of answerChoices){
		setTimeout(()=>{guess(answerChoice)},pause);	//No need to check given that it will record the correct answer anyways.
		pause += 1000;
	}
}
for(let question of questions){
	hackRadio(question);
}
questions = Array.from(document.querySelectorAll(".short-answer-question"));
async function hackShortAnswer(question){
	if(question.querySelector(".question-chevron").getAttribute("aria-label") == "Question completed") return;
	question.querySelector("textarea").value = question.querySelector(".forfeit-answer").textContent;
	//question.querySelector(".check-button").click(); They are smart bastards
}
for(let question of questions){
	const showAnswerButton = question.querySelector(".show-answer-button");
	showAnswerButton.click();
	showAnswerButton.click();
	hackShortAnswer(question);
}

export const Main = () => {
    const [title, setTitle] = useState('');
    
    return (
        <ChildComponent
            title={title}
            onChange={e => setTitle(e.target.value)}
        />
    );
};

export const ChildComponent = ({ title, onChange }) => {
    return (
        <Box component="form" onSubmit={() => {}} noValidate mt={5}>
            <TextField
                fullWidth
                id="title"
                label="Title"
                name="title"
                autoComplete="title"
                autoFocus
                color="primary"
                variant="filled"
                InputLabelProps={{ shrink: true }}
                value={title}
                onChange={onChange}
            />
        </Box>
    );
};

const geometricProgression = (end, start = 1, step = 2) =>
  Array.from({
    length: Math.floor(Math.log(end / start) / Math.log(step)) + 1,
  }).map((_, i) => start * step ** i);
  
geometricProgression(256); // [1, 2, 4, 8, 16, 32, 64, 128, 256]
geometricProgression(256, 3); // [3, 6, 12, 24, 48, 96, 192]
geometricProgression(256, 1, 4); // [1, 4, 16, 64, 256]