690. Employee Importance

  • 58.7%

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 direct subordinates’ 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.

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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.

方法一:

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/*
// Employee info
class Employee {
public:
// It's the unique ID of each node.
// unique id of this employee
int id;
// the importance value of this employee
int importance;
// the id of direct subordinates
vector<int> subordinates;
};
*/
class Solution {
public:
int getImportance(vector<Employee*> employees, int id) {
unordered_map<int, Employee*> map;
for(auto it:employees)
map[it->id] = it;
int res = 0;
helper(id, res, map);
return res;
}

void helper(int id, int& res, unordered_map<int, Employee*>& map){
res += map[id]->importance;
for(auto i:map[id]->subordinates)
helper(i, res, map);
return;
}
};

https://discuss.leetcode.com/topic/105382/c-dfs-using-stl

C++ DFS using STL

without STL

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class Solution {
public:
int getImportance(vector<Employee*> employees, int id) {

unordered_map<int, Employee*> map;

for(const auto element : employees){

map[element->id] = element;
}

return help(map, id);
}

int help(unordered_map<int, Employee*>& map, const int id){

auto sum = map[id]->importance;

for(const auto element : map[id]->subordinates){

sum += help(map, element);
}

return sum;
}
};
谢谢你,可爱的朋友。