1376 Time Needed to Inform All Employees

Question

My Solution:

class Solution {
    public int numOfMinutes(int n, int headID, int[] manager, int[] informTime) {
        Map<Integer, Integer> times = new HashMap<>();
        int max = 0; 
        for(int i = 0; i<n; i++){
            max = Math.max(max, dfs(i, manager, informTime, times));
        }
        
        return max;
    }
    
    private int dfs(int e_id, int[] manager, int[] informTime, Map<Integer, Integer> times){
        if(manager[e_id] == -1){
            return 0;
        }
        if(times.containsKey(e_id)){
            return times.get(e_id);
        }
        times.put(e_id, 
                  informTime[manager[e_id]]
                 + dfs(manager[e_id], manager, informTime, times));
        return times.get(e_id);
    }
}