Java的输入与输出

1_经典Scanner输入

最多只能支持到10^5,再增多就会TLE;

import java.util.Scanner;
public class Main
{
    public static void main(String[] str)
    {
        Scanner sc = new Scanner(System.in);
        int a , b;
        a = sc.nextInt();
        b = sc.nextInt();
        System.out.printf("%d" , (a + b));
    }
}

2_Buffered和Stream
需提前声明,并且抛异常；

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class Main
{
    public static void main(String[] args) throws Exception
    {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String s;
        s = br.readLine();
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        bw.write(s);
        bw.flush();
    }
}