Help Help With A Parsing Code!

[Alianza]

Hello guys,
I'm here with a new code I'm trying to make that I cannot get it out of my head  :rage:
So, here's my problem: I have two tables with information. Both of them have the same structure (ID, Value) but one of them has more repeated values than the other one. For example:
|----------------------|                    |----------------------|

| ID              Val   |                    | ID             Val    |

|----------------------|                    |----------------------|

| 1                 0    |                    | 1                 0    |

| 1                 0    |                    | 1                 0    |

| 2                 5    |                    | 1                 0    |

| 2                 5    |                    | 1                 0    |

| 2                 5    |                    | 2                 5    |

| 2                 5    |                    | 2                 5    |

| 3                 1    |                    | 2                 5    |

| 3                 1    |                    | 2                 5    |

-----------------------                     | 3                 1    |

                                                | 3                 1    |

                                                ------------------------

 

Here you can see two tables with the same structure but one of them has more repeated values than the other one (as I said before). What I'm trying to make, is the following: take the ID from the first table (ID = 1) and copy the value from the second table (Val = 0), but just copy it as many times as the ID in the first table exists. For example: if the ID 1 in the first table exists 2 times, copy the Val from the second table 2 times, skip the other two, and go to the next ID by doing the same.

I've tried to do it. The class I've made loads both tables and fills two ArrayLists with its information by putting them into an IntIntHolder class (thks aCis) in order to compare them later. So far, this is the code I've written, but it throws NoSuchElementException. And running it without the (see below), it prints some data but not all (if total data is 8, it prints 4).

while (elementA.getId() != elementB.getId())

Here's my code:

public void compareAndPrint()
{
	Iterator<IntIntHolder> iterA = listA.iterator();
	Iterator<IntIntHolder> iterB = listB.iterator();
	while (listA.hasNext())
	{
		IntIntHolder elementA = iterA.next();
		IntIntHolder elementB = iterB.next();
		if (elementA.getId() == elementB.getId())
			System.out.println(elementB.getValue());
		else
		{
                        while (elementA.getId() != elementB.getId())
			        iterB.next();
		}
	}
}

So ye... that's all. I'm trying to parse some data from the system so that's why I'm trying to do this.

Thanks for reading, and I'm looking forward to your answers!

[Alianza]

Okay mate. I will try to do so and I'll keep you updated.

Thank you!

 

EDIT: hehe, I've solved it following your steps.

Here's the code:

private final static Map<Integer, Integer> MAP = new LinkedHashMap<>();

public void compareAndGenerate()
{
	int i = 1;
	for (IntIntHolder aElement : listA)
	{
		if (!MAP.containsKey(aElement.getId()))
			i = 1;
		
		MAP.put(aElement.getId(), i++);
	}
	
	for (Entry<Integer, Integer> map : MAP.entrySet())
	{
		int ii = map.getValue();
		for (IntIntHolder bElement : listB)
		{
			if (bElement.getId() == map.getKey())
			{
				while (ii > 0)
				{
					System.out.println(bElement.getValue());
					ii--;
				}
			}
		}
	}
}

Thank you, very much.

You disserve a cookie. Here ya' go

 

Edited July 14, 2017 by Alianza

[Tryskell]

What happens if a same id got different values ?

 

What is supposed to be the third table, since I didn't understand anything (I don't see the point between the 2 tables at all, until you want to increment it but it's probably far better to simply use a Map<Integer, Integer> and increment it directly the second parameter) :D.

[Alianza]

Hello Tryskell, and thanks for replying!

Well, I'm trying to parse some system data as I said before, so I need to maintain those values as they appear there. I need to copy something from a higher chronicle to Interlude, which has less data.

For example:

 

Those are both tables. I'm trying to copy the values from the B table to the A table. Sometimes, the B table has more repeated values which increment its size compared to A table. What I'm trying to do, its to past through those repeated values and keep copying the other values that are not repeated and match with the A table (original Interlude data).

Is it clearer now?

 

EDIT: I forgot to say that I need to maintain the size. I cannot use a Map<Integer, Integer> because that will affect its size. I just need to copy values from table B to the IDs of  table A.

Edited July 13, 2017 by Alianza

[Tryskell]

No clue if there is an easier solution, I would count occurences of each id type on table A (with a stream() you can use .count() and can generate a temporary map holding id/occurences count), then on table B you for loop the whole thing, verify the current id and current occurence number. If occurence counter is superior to occurence count of the temp map, you "continue;". Once you changed of id you reset the occurence counter to 0.

[Alianza]

I cant see the logic there, sorry (I'm half stupid).

My logic is: when the ID of the A table and the ID of the B table are different, I just use iterB.next() to find the ID that matches the ID of the table A again and continue with the code. Am I wrong?

For some reason I cant do it (maybe because I'm half stupid).

Thanks again, Tryskell.

[Tryskell]

If id/values are correct on table 2, you only have to filter the number of IntIntHolder from this table to fit the count of table 1.

 

So you count occurences of table 1 : id 1 got 2 matches, id 2 got 4 matches, id 3 got 2 matches. You keep result in a temporary map.

 

Then you for loop the table 2 ; based on temporary map, you find id 1. Based on your temp map, it should have 2 occurences, but you find more. You add the 2 first, and don't bother about leftover (continue). Then you got on another id, etc etc.

[Celestine]

Solved Locked.