MinOccurance2.java

import java.io.*;

public class MinOccurance2
{
  public static void main (String[] args) throws IOException
  {
    int[] occur = new int[256]; 
    int Current = 0;
    
    RandomAccessFile file = new RandomAccessFile("test.txt", "r");
    long length = file.length();
    for ( int i = 0; i < length; i++) {
 
    Current = file.read();

    int highNibble = Current >>> 4 ;
    int lowNibble = Current & 0x0f;


    occur[highNibble]++;
    occur[lowNibble]++;
    }
    
    for ( int k = 0; k < 4; k++) {

      System.out.println(k + " " + occur[k]);

    }

    
  }
}