CCF2016.4 - C题

思路：先把路径按反斜杠split成数组，然后用一个ArrayList去模拟。如果遇到空或者.则不处理；如果遇到..则删除ArrayList最后一个元素（注意如果只有1个元素则不删除）；其他情况直接加到ArrayList里面。注意特判输入空串的情况。

 import java.util.*;
 public class Main {
     public static void main(String[] args) {
         Scanner cin = new Scanner(System.in);
         int n = cin.nextInt();
         String curPath = cin.next();
         String[] curPathArr = curPath.split("/", -1);
         cin.nextLine();
         while (n-- > 0) {
             String path = cin.nextLine();
             if (path.length() == 0)
                 System.out.println(curPath);
             else {
                 String[] pathArr = path.split("/", -1);
                 ArrayList<String> resultArr = new ArrayList<String>();
                 int st = 1;
                 if (pathArr[0].length() == 0)
                     resultArr.add("");
                 else {
                     for (String s : curPathArr)
                         resultArr.add(s);
                     st = 0;
                 }
                 for (int i = st; i < pathArr.length; i++) {
                     if (pathArr[i].equals("..")) {
                         if (resultArr.size() > 1)
                             resultArr.remove(resultArr.size() - 1);
                     }
                     else if (!pathArr[i].equals(".") && !pathArr[i].equals(""))
                         resultArr.add(pathArr[i]);
                 }
                 if (resultArr.size() == 1)
                     System.out.println("/");
                 else {
                     for (int i = 0; i < resultArr.size() - 1; i++)
                         System.out.print(resultArr.get(i) + "/");
                     System.out.println(resultArr.get(resultArr.size() - 1));
                 }
             }
         }
     }
 }