toantd90

function upperBound(arr, start, end, value) {
  while (start <= end) {
    const mid = start + Math.floor((end - start) / 2);

    if (arr[mid] > value) {
      end = mid - 1;
    } else {
      start = mid + 1;
    }
  }

toantd90

class DSU {
  constructor(n) {
    this.ranks = [];
    this.parent = [];

    for (let i = 0; i < n; i++) {
      this.ranks[i] = 0;
      this.parent[i] = i;
    }

toantd90

function lowerBound(arr, start, end, value) {
  while (start < end) {
    const mid = start + Math.floor((end - start) / 2)
    
    if (arr[mid] < value) {
      start = mid + 1
    } else {
      end = mid
    }
  }

toantd90

/**
 * @param {character[][]} board
 * @param {number[]} click
 * @return {character[][]}
 */
var updateBoard = function(board, click) {
  const clickL = click[0], clickR = click[1];
  if (board[clickL][clickR] === 'M') {
    board[clickL][clickR] = 'X';
    return board;

toantd90

/**
 * @param {string} s
 * @param {string} t
 * @return {boolean}
 */
var isSubsequence = function(s, t) {
    const len = s.length;
    if (len === 0) return true;
    
    let sIndex = 0;

toantd90

/**
 * @param {string} s
 * @return {number}
 */
const romanToInt = function(s) {
    const map = {
        'I': 1,
        'V': 5,
        'X': 10,
        'L': 50,