백준 1516 - 게임 개발

import java.io.FileInputStream;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
import java.util.Stack;
 
public class Main {
 
    static ArrayList<Integer>[] aList;
    static int indegree[];
    static int N;
    static boolean T = true;
    static int[] time;
    static int[] getTime;
 
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
 
        N = sc.nextInt();
        aList = new ArrayList[N + 1];
        indegree = new int[N + 1];
        time = new int[N + 1];
        getTime = new int[N + 1];
 
        for (int i = 1; i <= N; i++) {
            aList[i] = new ArrayList<Integer>();
        }
        for (int i = 1; i <= N; i++) {
            T = true;
            int sec = sc.nextInt();
 
            time[i] = sec;
            while (T) {
                int a = sc.nextInt();
                if (a == -1) {
                    T = false;
                } else {
                    aList[i].add(a);
                    indegree[a]++;
                }
            }
        }
 
        result();
 
        sc.close();
 
    }
 
    private static void result() {
        Queue<Integer> que = new LinkedList<Integer>();
        Stack<Integer> s = new Stack<Integer>();
 
        for (int i = 1; i < aList.length; i++) {
            if (indegree[i] == 0) {
                que.offer(i);
            }
        }
 
        while (!que.isEmpty()) {
            int q = que.poll();
 
            s.push(q);
 
            for (int i = 0; i < aList[q].size(); i++) {
                int getaList = aList[q].get(i);
                indegree[getaList]--;
 
                if (indegree[getaList] == 0) {
                    que.offer(getaList);
                }
            }
        }
 
        while (!s.isEmpty()) {
            int spop = s.pop();
 
            getTime[spop] = ((aList[spop].size() == 0) ? time[spop] : time[spop] + maxs(spop));
        }
 
        for(int i = 1; i<getTime.length; i++) { 
            System.out.println(getTime[i]); 
        } 
    }
 
    private static int maxs(int a) {
 
        int max = 0;
        
        for (int i = 0; i < aList[a].size(); i++) {
            
            int b = aList[a].get(i);
            
            max = Math.max(max, getTime[b]);
        }
        
 
        return max;
    }
}