这次生病了拖了这么久才做完这次的题

/**
 * @param {number[][]} coordinates
 * @return {boolean}
 */
var checkStraightLine = function (coordinates) {
  const n = coordinates.length;
  if (n === 2) return true;
  const a = coordinates[0][0] - coordinates[1][0], b = coordinates[0][1] - coordinates[1][1];
  for (let i = 2; i < n; i++) if ((coordinates[i][0] - coordinates[i - 1][0]) * b !== (coordinates[i][1] - coordinates[i - 1][1]) * a) return false;
  return true;
};


/**
 * @param {string[]} folder
 * @return {string[]}
 */
function T(bool, val) {
  this.val = val;
  this.end = bool;
  this.children = [];
}
var removeSubfolders = function (folder) {
  const m = new T(false, '/');
  function h(arr, val) {
    for (const i in arr) if (arr[i].val === val) return i;
    return -1;
  }
  for (const f of folder) {
    const fArr = f.split('/');
    if (fArr[0] === '') fArr.shift();
    if (fArr.length === 0) continue;
    let t = m;
    for (let i = 0; i < fArr.length; i++) {
      const index = h(t.children, fArr[i]);
      if (index !== -1) {
        if (t.end || t.children[index].end) break;
        if (i === fArr.length - 1) t.children[index].end = true;
        t = t.children[index];
      } else {
        if (i === fArr.length - 1) t.children.push(new T(true, fArr[i]));
        else t.children.push(new T(false, fArr[i]));
        t = t.children[t.children.length - 1];
      }
    }
  }
  let s = '';
  const r = [];
  function dfs(root) {
    if (root.children && root.children.length > 0) {
      for (const a of root.children) {
        const ttt = s;
        s += '/' + a.val;
        if (a.end) {
          r.push(s);
          s = ttt;
          continue;
        }
        dfs(a);
        s = ttt;
      }
    }
  }
  dfs(m)
  return r;
};


// 滑动窗口的常规做法, 使窗口外的字母符合题目中的条件, 符合之后往后移动窗口, 找到符合条件的最小的窗口.
/**
 * @param {string} s
 * @return {number}
 */
var balancedString = function (s) {
  const n = s.length, nn = n / 4, m = { Q: 0, W: 0, E: 0, R: 0 };
  let l = 0, r = 0, min = n;
  for (const c of s)++m[c];
  while (r <= n) {
    if (m['Q'] > nn || m['W'] > nn || m['E'] > nn || m['R'] > nn)--m[s[r++]];
    else {
      if (r - l < min) min = r - l;
      if (min === 0) break;
      ++m[s[l++]];
    }
  }
  return min;
};


// dp问题, dp[i] = 结束时间为 i 获得的最大利润, 
// dp[i] = 结束时间为i的任务的开始时间j之前可以获得的最大利润
/**
 * @param {number[]} startTime
 * @param {number[]} endTime
 * @param {number[]} profit
 * @return {number}
 */
var jobScheduling = function (startTime, endTime, profit) {
  const lowerBound = function (arr2, val) {
    let f = 0, arr = arr2[0], l = arr.length;
    if (val > arr[l - 1]) return l - 1;
    if (val < arr[0]) return 0;
    let m;
    while (f < l) {
      m = f + parseInt((l - f) / 2);
      if (arr[m] < val) f = m + 1;
      else if (arr[m] === val) return m;
      else l = m;
    }
    return f - 1;
  }
  const n = startTime.length, dp = [[0], [0]], jobs = [];
  for (let i = 0; i < n; i++) jobs[i] = [startTime[i], endTime[i], profit[i]];
  jobs.sort((a, b) => a[1] - b[1]);
  for (const [s, e, p] of jobs) {
    const cur = dp[1][lowerBound(dp, s)] + p;
    if (cur > dp[1][dp[1].length - 1]) { dp[0].push(e); dp[1].push(cur); }
  }
  return dp[1][dp[1].length - 1];
};