Employee Importance
<p>You have a data structure of employee information, including the employee&#39;s unique ID, importance value, and direct subordinates&#39; IDs.</p>

<p>You are given an array of employees <code>employees</code> where:</p>

<ul>
	<li><code>employees[i].id</code> is the ID of the <code>i<sup>th</sup></code> employee.</li>
	<li><code>employees[i].importance</code> is the importance value of the <code>i<sup>th</sup></code> employee.</li>
	<li><code>employees[i].subordinates</code> is a list of the IDs of the direct subordinates of the <code>i<sup>th</sup></code> employee.</li>
</ul>

<p>Given an integer <code>id</code> that represents an employee&#39;s ID, return <em>the <strong>total</strong> importance value of this employee and all their direct and indirect subordinates</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0600-0699/0690.Employee%20Importance/images/emp1-tree.jpg" style="width: 400px; height: 258px;" />
<pre>
<strong>Input:</strong> employees = [[1,5,[2,3]],[2,3,[]],[3,3,[]]], id = 1
<strong>Output:</strong> 11
<strong>Explanation:</strong> Employee 1 has an importance value of 5 and has two direct subordinates: employee 2 and employee 3.
They both have an importance value of 3.
Thus, the total importance value of employee 1 is 5 + 3 + 3 = 11.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0600-0699/0690.Employee%20Importance/images/emp2-tree.jpg" style="width: 362px; height: 361px;" />
<pre>
<strong>Input:</strong> employees = [[1,2,[5]],[5,-3,[]]], id = 5
<strong>Output:</strong> -3
<strong>Explanation:</strong> Employee 5 has an importance value of -3 and has no direct subordinates.
Thus, the total importance value of employee 5 is -3.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= employees.length &lt;= 2000</code></li>
	<li><code>1 &lt;= employees[i].id &lt;= 2000</code></li>
	<li>All <code>employees[i].id</code> are <strong>unique</strong>.</li>
	<li><code>-100 &lt;= employees[i].importance &lt;= 100</code></li>
	<li>One employee has at most one direct leader and may have several subordinates.</li>
	<li>The IDs in <code>employees[i].subordinates</code> are valid IDs.</li>
</ul>
Tree; Depth-First Search; Breadth-First Search; Array; Hash Table
/*
// Definition for Employee.
class Employee {
public:
    int id;
    int importance;
    vector<int> subordinates;
};
*/

class Solution {
public:
    int getImportance(vector<Employee*> employees, int id) {
        unordered_map<int, Employee*> d;
        for (auto& e : employees) {
            d[e->id] = e;
        }
        function<int(int)> dfs = [&](int i) -> int {
            int s = d[i]->importance;
            for (int j : d[i]->subordinates) {
                s += dfs(j);
            }
            return s;
        };
        return dfs(id);
    }
};