Given a stream of characters, implement a method that will always return the first character that has only appeared once in the stream. For example, say your stream thus far is a,b,c. A call into getFirstUniqueCharacter would return a. After the next character is read, the stream thus far is a,b,c,a. Now a call to getFirstUniqueCharacter will re…

possible solution

InputStream is = null;
      int i;
      char c;
      
      try{
         // new input stream created
         is = new FileInputStream("C://test.txt");
         
         System.out.println("Characters printed:");
         
         // reads till the end of the stream
         while((i=is.read())!=-1)
         {
            // converts integer to character
            c=(char)i;
            
            // prints first character that has only appeared once in the stream
            System.out.print(getFirstUniqueCharacter(c));
         }
      }catch(Exception e){
         
         // if any I/O error occurs
         e.printStackTrace();
      }finally{
         
         // releases system resources associated with this stream
         if(is!=null)
            is.close();
      }
 
//Write the implementation for getFirstUniqueCharacter

/*implement a method that will always return the first character that has only appeared once in the stream*/
//thinking it over, for example my name its orederd 
//so it will first return the first letter then save and compare to the next, even if not called in stream, it will still be counted
// example vitalianovidaurre
//crate a has, and array
//array order, hash freq,
//if key is null, unique, if key exists, its been repeated
import java.util.HashMap;
import java.util.ArrayList;
import java.util.Map;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;

public char getFirstUniqueCharacter(char c)
{
    //HashTable<char, bool> saver = new HashTable<char, bool>();
    Map<Character, Integer> counts = new LinkedHashMap<>str.length();
    char[] verifier = new char[];
    
 
    for(char c : str.tCharArray())
    {
        counts.put(c, counts.containsKey(c) ? counts.get(c) +1 : 1); //if found key, put it in map   
    }
    for(Entry<Character, Integer> entry : counts.entrySet(){ //go through map to see if there are any new values
        if(entry.getValue()==1)
        {
            char key;
            key=entry.getKey();
          
            return key;
            System.Out.Println("found  repeated char {0}", key);
            //first element from list is the first non repeated char from string
        }
        
    }
      System.Out.Println("didnt find any non repeated char");
}