java题目截取字符串

 

 

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

public class Main{
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        String line = "";
        while((line = br.readLine()) != null) {
            int n = Integer.parseInt(br.readLine());
            String newLine = line.substring(0,n);  //生成子字符串从索引0到n，不包含结尾
            System.out.println(newLine);
        }
    }
}