奇安信笔试-结束进程数

package leetcode;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

/**
 * @author 江河
 * @date 2019-09-09 20:16
 */
public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    while (sc.hasNext()){
      //输入第一行
      String str1 = sc.nextLine();
      String[] numstr1 = str1.split(" ");
      int[] num1 = new int[numstr1.length];
      List pids = new ArrayList<>();
      for(int i = 0; i < numstr1.length; i ++) {
        num1[i] = Integer.parseInt(numstr1[i]);
        pids.add(num1[i]);
      }
      //输入第二行
      String str2 = sc.nextLine();
      String[] numstr2 = str2.split(" ");
      int[] num2 = new int[numstr2.length];
      List ppids = new ArrayList<>();
      for(int i = 0; i < numstr2.length; i ++) {
        num2[i] = Integer.parseInt(numstr2[i]);
        ppids.add(num2[i]);
      }
      //输入第三行
      String str3 = sc.nextLine();
      String[] numstr3 = str3.split(" ");
      int[] num3 = new int[numstr3.length];
      num3[0] = Integer.parseInt(numstr3[0]);
      int kills= num3[0];
      List ss = killProcess(pids,ppids,kills);
      int x= ss.size();
      System.out.println(x);
    }

  }

  /**
   * 下面是一个找遍历的递归的树是个集合
   * @param pid
   * @param ppid
   * @param kill
   * @return
   */
  public static List killProcess(List pid, List ppid, int kill) {
    ArrayList ans = new ArrayList();
    ans.add(kill);
    for (int i = 0; i < ppid.size(); i++) {
      if (ppid.get(i) == kill) {
        ans.addAll(killProcess(pid, ppid, pid.get(i)));
      }
    }
    return ans;
  }
}