Assignment 4

 import java.io.*;
 import static java.lang.System.*;
 import java.util.Random;
 import java.util.Scanner;
 import java.lang.Math;

 class Main{


      public static void main (String str[]) throws IOException {
        Scanner scan = new Scanner(System.in);

        String tweet;
        int refs = 0;
        int rt = 0;
        int ht = 0;
        System.out.println("Please enter a tweet:");
        tweet = scan.nextLine();
        if (tweet.length() > 140)
        {
          System.out.println("Excess Characters: " + (tweet.length() - 140));
        }
        else
        {
          System.out.println("Length Correct");
          for(int i = 0; i < tweet.length(); i++)
          {
            if (tweet.charAt(i) == '@')
            {
               if(i < tweet.length()-1)
              {
              if (tweet.charAt(i+1) == ' ')
                    refs += 0;
              else if (tweet.charAt(i+1) == '\t')
                    refs += 0;
              else
                    refs++;
               }
            }
          }
          System.out.println("Number of Mentions: " + refs);
          //
          for(int i = 0; i < tweet.length(); i++)
          {
            if (tweet.charAt(i) == '#')
            {
              if(i < tweet.length()-1)
              {
              if (tweet.charAt(i+1) == ' ')
                    ht += 0;
              else if (tweet.charAt(i+1) == '\t')
                    ht += 0;
              else
                    ht++;
              }
            }
          }
          System.out.println("Number of Hashtags: " + ht);
          //
          tweet = tweet.toUpperCase();
          for(int i = 0; i < tweet.length(); i++)
          {
             if (tweet.charAt(i) == 'R' && tweet.charAt(i+1) == 'T' && tweet.charAt(i+2) == ':')
            {
              rt++;
            }
          }
          if(rt > 0)
            System.out.println("The input was a retweet.");
          else
            System.out.println("The input was not a retweet.");
        }
      }
 }