IO流 （附带算法竞赛模板）

主要是BufferedReader + StringTokenizer（很快）

算法竞赛模板:

import java.io.*;  
import java.math.BigDecimal;  
import java.math.BigInteger;  
import java.util.StringTokenizer;  
public class Main {  
    public static void solve() {  
            
    }  
    public static void main(String[] args) throws Exception {  
         try (PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out))) {  
             int t = in.nextInt();  
             while (t-- > 0) {  
                 solve();  
             }         
          } catch (Exception e) {  
             e.printStackTrace();  
          }    
    }  
  
  
    static InputReader in = new InputReader();  
    static class InputReader{  
        private StringTokenizer st;  
        private BufferedReader bf;  
  
        public InputReader() {  
            bf = new BufferedReader(new InputStreamReader(System.in));  
            st = null;  
        }  
        public String next() throws IOException{  
            while(st == null || !st.hasMoreTokens()) {  
                st = new StringTokenizer(bf.readLine());  
            }            
            return st.nextToken();  
        }  
        public String nextLine() throws IOException{  
            return bf.readLine();  
        }  
        public int nextInt() throws IOException{  
            return Integer.parseInt(next());  
        }  
        public long nextLong() throws IOException{  
            return Long.parseLong(next());  
        }  
        public double nextDouble() throws IOException{  
            return Double.parseDouble(next());  
        }  
        public BigInteger nextBigInteger() throws IOException{  
            return new BigInteger(next());  
        }  
        public BigDecimal nextBigDecimal() throws IOException{  
            return new BigDecimal(next());  
        }    
    }
}