## Thursday, May 10, 2018

### LeetCode 690 - Employee Importance

https://leetcode.com/problems/employee-importance/description/
You are given a data structure of employee information, which includes the employee's unique id, his importance value and his directsubordinates' id.
For example, employee 1 is the leader of employee 2, and employee 2 is the leader of employee 3. They have importance value 15, 10 and 5, respectively. Then employee 1 has a data structure like [1, 15, [2]], and employee 2 has [2, 10, [3]], and employee 3 has [3, 5, []]. Note that although employee 3 is also a subordinate of employee 1, the relationship is not direct.
Now given the employee information of a company, and an employee id, you need to return the total importance value of this employee and all his subordinates.
Example 1:
```Input: [[1, 5, [2, 3]], [2, 3, []], [3, 3, []]], 1
Output: 11
Explanation:
Employee 1 has importance value 5, and he has two direct subordinates: employee 2 and employee 3. They both have importance value 3. So the total importance value of employee 1 is 5 + 3 + 3 = 11.
```
Note:
1. One employee has at most one direct leader and may have several subordinates.
2. The maximum number of employees won't exceed 2000.

Map<Integer, Employee> emap;
public int getImportance(List<Employee> employees, int queryid) {
emap = new HashMap();
for (Employee e: employees) emap.put(e.id, e);
return dfs(queryid);
}
public int dfs(int eid) {
Employee employee = emap.get(eid);
int ans = employee.importance;
for (Integer subid: employee.subordinates)
ans += dfs(subid);
return ans;
}

public int getImportance(List<Employee> employees, int id) {
Map<Integer, Employee> map = employees.stream().collect(Collectors.toMap(e -> e.id, Function.identity()));
return getImportanceImpl(map, id);
}

public int getImportanceImpl(Map<Integer, Employee> employees, int id) {

Employee employee = employees.get(id);
int result = employee.importance;
if (employee.subordinates.isEmpty()) {
return result;
}

for (Integer subId : employee.subordinates) {
result += getImportanceImpl(employees, subId);
}
return result;

}