【Codeforces 158C】Cd and pwd commands

【链接】 我是链接,点我呀:)

【题意】

让你实现Shell的cd和pwd操作

【题解】

用一个list表示当前的路径
如果路径以/开头则表示需要清空当前路径重新走路
否则在原来路径的基础上继续加就可以了

【代码】

import java.io.*;
import java.util.*;

public class Main {

	static InputReader in;
	static PrintWriter out;

	public static void main(String[] args) throws IOException{
		//InputStream ins = new FileInputStream("E:\\rush.txt");
		InputStream ins = System.in;
		in = new InputReader(ins);
		out = new PrintWriter(System.out);
		//code start from here
		new Task().solve(in, out);
		out.close();
	}

	static int N = (int)3000;
	static class Task{
		ArrayList cwd= new ArrayList();

		String getCWD() {
			StringBuilder sb = new StringBuilder("/");
			for (int i = 0;i < cwd.size();i++) {
				String s = (String)cwd.get(i);
				sb.append(s+"/");
			}
			return sb.toString();
		}

		public void solve(InputReader in,PrintWriter out) {
			int n;
			n = in.nextInt();
			for (int i = 1;i <= n;i++) {
				String ope = in.next();
				if (ope.equals(new String("pwd"))) {
					out.println(getCWD());
				}else {
					String p = in.next();
					String []parameters;
					if (p.charAt(0)=='/') {
						cwd.clear();
						parameters = p.substring(1,p.length()).split("/");
					}else {
						parameters = p.split("/");
					}
					for (int j = 0;j < parameters.length;j++) {

						if (!parameters[j].equals("..")) {
							cwd.add(parameters[j]);
						}else {
							cwd.remove((int)cwd.size()-1);
						}
					}
				}
			}
		}
	}

	static class InputReader{
		public BufferedReader br;
		public StringTokenizer tokenizer;

		public InputReader(InputStream ins) {
			br = new BufferedReader(new InputStreamReader(ins));
			tokenizer = null;
		}

		public String next(){
			while (tokenizer==null || !tokenizer.hasMoreTokens()) {
				try {
				tokenizer = new StringTokenizer(br.readLine());
				}catch(IOException e) {
					throw new RuntimeException(e);
				}
			}
			return tokenizer.nextToken();
		}

		public int nextInt() {
			return Integer.parseInt(next());
		}
	}
}