Count and Say


/*Lets write an algorithm that, given an initial value, will produce the next 'count and say' sequence:
1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, …
*/

public class CountAndSay{

  public static void main(String[] args){

     System.out.println("Count and Say algorithm");

     System.out.println("next sequence is: " + countAndSay(args[0].toString()));

  }

  public static String countAndSay(String input){

     Boolean change=false;
     String output="";
     int count=1;

     char[] str = input.toCharArray();

     System.out.println("Input is: " + input);

     for (int i=0;i<str.length;i++){

       if (i+1<str.length && str[i]==str[i+1]){
          count++;
       }
       else{
          output = output + count + str[i];
          count=1;
       }

     }

     return output;

  }

}

 

 

Listen on a port/Send data to a port


Listening with nc:

nc -l 8089

Checking that 8089 port is listening:

netstat -nap|grep 8089
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 0.0.0.0:8089 0.0.0.0:* LISTEN 27543/nc
tcp 0 0 127.0.0.1:8089 127.0.0.1:43592 TIME_WAIT -

Sending data to 8089 port:

telnet localhost 8089
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
hello

 

listeningOnAPort_SendingDataToAPort