1376-time-needed-to-inform-all-employees.js

/**
 * 1376. Time Needed to Inform All Employees
 * https://leetcode.com/problems/time-needed-to-inform-all-employees/
 * Difficulty: Medium
 *
 * A company has n employees with a unique ID for each employee from 0 to n - 1. The head
 * of the company is the one with headID.
 *
 * Each employee has one direct manager given in the manager array where manager[i] is the
 * direct manager of the i-th employee, manager[headID] = -1. Also, it is guaranteed that
 * the subordination relationships have a tree structure.
 *
 * The head of the company wants to inform all the company employees of an urgent piece of
 * news. He will inform his direct subordinates, and they will inform their subordinates,
 * and so on until all employees know about the urgent news.
 *
 * The i-th employee needs informTime[i] minutes to inform all of his direct subordinates
 * (i.e., After informTime[i] minutes, all his direct subordinates can start spreading the news).
 *
 * Return the number of minutes needed to inform all the employees about the urgent news.
 */

/**
 * @param {number} n
 * @param {number} headID
 * @param {number[]} manager
 * @param {number[]} informTime
 * @return {number}
 */
var numOfMinutes = function(n, headID, manager, informTime) {
  const adjacencyList = Array.from({ length: n }, () => []);

  for (let i = 0; i < n; i++) {
    if (manager[i] !== -1) {
      adjacencyList[manager[i]].push(i);
    }
  }

  return calculateTime(headID);

  function calculateTime(employee) {
    let maxSubordinateTime = 0;

    for (const subordinate of adjacencyList[employee]) {
      maxSubordinateTime = Math.max(maxSubordinateTime, calculateTime(subordinate));
    }

    return informTime[employee] + maxSubordinateTime;
  }
};