moectf2020 write up for Frank，永远滴神

这道题要我们统计所有文本文件中字符串FrankNB!的出现次数~

直接用Java写轻松些，以及偷懒没写高级的字符串匹配算法（毕竟不会像OI那样TLEwwwwww）

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

public class Test
{

    public static int searchString(String path)
    {
        File file = new File(path);
        int num = 0;

        if(file.isDirectory())//if the variable "file" is a directory, files in it will be searched in recursion
        {
            boolean exist = false;
            File[] files = file.listFiles();

            for(File f:files)
            {
                num += searchString(path+"\\"+f.getName());
            }
            return num;
        }
        else
        {
            try (FileInputStream fileInputStream = new FileInputStream(file))
            {
                FileOutputStream fileOutputStream = new FileOutputStream(new File("test.txt"));
                int c, index = 0;
                String str = "";
                char[] frk = {'F','r','a','n','k','N','B','!'};
                while((c = fileInputStream.read()) != -1)//EOF
                {
                    str += String.valueOf((char)c);
                }
                int len = str.length();
                for(int i=0;i<len;i++)
                {
                    c = str.charAt(i);
                    if(c == frk[index])
                    {
                        index++;
                        if(c == '!')
                        {
                            index = 0;
                            num++;
                        }
                    }
                    else
                    {
                        i-=index;
                    
                        index = 0;
                    }
                }
            }
            catch (Exception e)
            {
                System.out.print("\n"+file.getAbsolutePath());
                e.printStackTrace();
            }
            return num;
        }
    }

    public static void main(String[] args)
    {
        System.out.println(searchString(args[0]));
    }
}

得到205232次

base64编码即得flag> <

moectf{MjA1MjMy}