【Codeforces 522A】Reposts

【链接】 我是链接,点我呀:)

【题意】

有人转载官方号的动态。
又有其他人转载其他人转载的动态.
问你最长的一条转载动态的链有多长.

【题解】

用map把每个人的英文都转成小写的
然后从map中获取单词的标号
转换成图。
然后从根节点开始dfs即可

【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)400;
	static class Task{
		int n,cnt,ans = 0;
		ArrayList []g;

		void dfs(int x,int dep) {
			ans = Math.max(ans,dep);
			for (int i = 0;i < (int)g[x].size();i++) {
				int y = (int)g[x].get(i);
				dfs(y,dep+1);
			}
		}

		public void solve(InputReader in,PrintWriter out) {
			g = new ArrayList[N+10];
			HashMap<String,Integer> dic = new HashMap<String,Integer>();
			for(int i = 1;i <= N;i++)g[i] = new ArrayList();
			n = in.nextInt();
			for (int i = 0;i < n;i++) {
				StringBuilder sb1 = new StringBuilder();
				StringBuilder sb2 = new StringBuilder();
				String s1,s2;

				s1 = in.next();s2 = in.next();s2 = in.next();

				char key;
				for (int j = 0;j < (int)s1.length();j++) {
					if (s1.charAt(j)>='A' && s1.charAt(j)<='Z') {
						key = (char)(s1.charAt(j)-'A'+'a');
						sb1.append(key);
					}else {
						key =(char)s1.charAt(j);
						sb1.append(s1.charAt(j));
					}
				}
				s1 = sb1.toString();

				for (int j = 0;j < (int)s2.length();j++) {
					if (s2.charAt(j)>='A' && s2.charAt(j)<='Z') {
						key = (char)(s2.charAt(j)-'A'+'a');
						sb2.append(key);
					}else {
						key =(char)s2.charAt(j);
						sb2.append(key);
					}
				}
				s2 = sb2.toString();

				if (!dic.containsKey(s1)) {
					dic.put(s1, ++cnt);
				}

				if (!dic.containsKey(s2)) {
					dic.put(s2, ++cnt);
				}

				int x = dic.get(s1),y = dic.get(s2);
				g[y].add(x);
			}
			dfs(dic.get("polycarp"),1);
			out.println(ans);
		}
	}

	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());
		}
	}
}