const kMeans = (data, k = 1) => {
  const centroids = data.slice(0, k);
  const distances = Array.from({ length: data.length }, () =>
    Array.from({ length: k }, () => 0)
  );
  const classes = Array.from({ length: data.length }, () => -1);
  let itr = true;

  while (itr) {
    itr = false;

    for (let d in data) {
      for (let c = 0; c < k; c++) {
        distances[d][c] = Math.hypot(
          ...Object.keys(data[0]).map(key => data[d][key] - centroids[c][key])
        );
      }
      const m = distances[d].indexOf(Math.min(...distances[d]));
      if (classes[d] !== m) itr = true;
      classes[d] = m;
    }

    for (let c = 0; c < k; c++) {
      centroids[c] = Array.from({ length: data[0].length }, () => 0);
      const size = data.reduce((acc, _, d) => {
        if (classes[d] === c) {
          acc++;
          for (let i in data[0]) centroids[c][i] += data[d][i];
        }
        return acc;
      }, 0);
      for (let i in data[0]) {
        centroids[c][i] = parseFloat(Number(centroids[c][i] / size).toFixed(2));
      }
    }
  }

  return classes;
};
kMeans([[0, 0], [0, 1], [1, 3], [2, 0]], 2); // [0, 1, 1, 0]

//Use at https://mee6.xyz/leaderboard/732262089447702588
//Higher the spammy stat, the more spammy that person is.
//This is because mee doesn't give experience to people who post more comments in a minute.
function statBlock(title, value){
	let elm = document.createElement("div");
	elm.className = "leaderboardPlayerStatBlock";
	let titleElm = document.createElement("div");
	titleElm.className = "leaderboardPlayerStatName";
	titleElm.textContent = title;
	let valueElm = document.createElement("div");
	valueElm.className = "leaderboardPlayerStatValue";
	valueElm.textContent = value;
	elm.appendChild(titleElm);
	elm.appendChild(valueElm);
	elm.remove = function(){
	this.parentElement.removeChild(this);
	}
	return elm;
}
for(let player of Array.from(document.getElementsByClassName("leaderboardPlayer"))){
	if(player.spamminess) player.spamminess.remove();
	let messages = null;
	let experience = null;
	const statBlockArray = Array.from(player.querySelectorAll(".leaderboardPlayerStatBlock"));
	for(let statBlock of statBlockArray){
	const statName = statBlock.querySelector(".leaderboardPlayerStatName").textContent;
	const text = statBlock.querySelector(".leaderboardPlayerStatValue").textContent;
	const number = ((text.includes("k"))? (text.replace("k","") * 1000.0) : +(text));
	if(statName.includes("MESSAGES")){
	messages = number;
	}else if(statName.includes("EXPERIENCE")){
	experience = number;
	}
	}
	const stats = player.querySelector(".leaderboardPlayerStats");
	const messagesElement = stats.firstChild;

	const spamminess = ((messages/experience)*2000.0).toFixed(2);
	
	player.spamminess = stats.insertBefore(statBlock("SPAMMINESS", spamminess), messagesElement);
}

const longestPalindrome = (s) => {
    if(s.length === 1) return s
    
    const odd = longestOddPalindrome(s)
    const even = longestEvenPalindrome(s)
    
    
    if(odd.length >= even.length) return odd
    if(even.length > odd.length) return even
};

const longestOddPalindrome = (s) => {    
    let longest = 0
    let longestSubStr = ""
    
    for(let i = 1; i < s.length; i++) {
        
        let currentLongest = 1
        let currentLongestSubStr = ""
        let left = i - 1
        let right = i + 1
        
        while(left >= 0 && right < s.length) {
            const leftLetter = s[left]
            const rightLetter = s[right]

            left--
            right++

            if(leftLetter === rightLetter) {
                currentLongest += 2
                currentLongestSubStr = s.slice(left+1, right)
            } else break
        }
        
                        
        if(currentLongest > longest) {
            if(currentLongestSubStr) longestSubStr = currentLongestSubStr 
            else longestSubStr = s[i]
            longest = currentLongest
        }
    }
    
    return longestSubStr
}

const longestEvenPalindrome = (s) => {    
    let longest = 0
    let longestSubStr = ""
    
    for(let i = 0; i < s.length - 1; i++) {
        if(s[i] !== s[i+1]) continue;
        
        let currentLongest = 2
        let currentLongestSubStr = ""
        let left = i - 1
        let right = i + 2
        
        while(left >= 0 && right < s.length) {
            const leftLetter = s[left]
            const rightLetter = s[right]

            left--
            right++
            
            if(leftLetter === rightLetter) {
                currentLongest += 2
                currentLongestSubStr = s.slice(left+1, right)
            } else break
        }
                
                
        if(currentLongest > longest) {
            if(currentLongestSubStr) longestSubStr = currentLongestSubStr
            else longestSubStr = s[i] + s[i+1]
    
            longest = currentLongest
        }
    }
    
    return longestSubStr
}
console.log(longestPalindrome("babad"))

const bucketSort = (arr, size = 5) => {
  const min = Math.min(...arr);
  const max = Math.max(...arr);
  const buckets = Array.from(
    { length: Math.floor((max - min) / size) + 1 },
    () => []
  );
  arr.forEach(val => {
    buckets[Math.floor((val - min) / size)].push(val);
  });
  return buckets.reduce((acc, b) => [...acc, ...b.sort((a, b) => a - b)], []);
};

bucketSort([6, 3, 4, 1]); // [1, 3, 4, 6]

const primes = num => {
  let arr = Array.from({ length: num - 1 }).map((x, i) => i + 2),
    sqroot = Math.floor(Math.sqrt(num)),
    numsTillSqroot = Array.from({ length: sqroot - 1 }).map((x, i) => i + 2);
  numsTillSqroot.forEach(x => (arr = arr.filter(y => y % x !== 0 || y === x)));
  return arr;
};

primes(10); // [2, 3, 5, 7]

function printHeap(heap, index, level) {
    if (index >= heap.length) {
        return;
    }
    console.log("  ".repeat(level) + heap[index]);
    printHeap(heap, 2 * index + 1, level + 1);
    printHeap(heap, 2 * index + 2, level + 1);
}

//You can call this function by passing in the heap array and the index of the root node, which is typically 0, and level = 0.

let heap = [3, 8, 7, 15, 17, 30, 35, 2, 4, 5, 9];
printHeap(heap,0,0)