I have a table with lat, long, location name. I have calculated the nearest distance from the current location and added the distance in one arraylist and then sorted in ascending order. Next i have added name in other arraylist. Now i need to set the names in the order using the distance from other list. How to do it?
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5 Answers
I think you are using arrays too extensively here. If you have two or more pieces of related data, you should not put each piece into a separate array. Instead create a class to hold all the related data (lat, long, distance and name) and have an array (or some other collection that better meets your needs such as a SortedList) that holds instances of this class. The class could implement Comparable using distance as the measure and therefore allow sorting by distance.
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are your distances calculated by latitude, longtitude in that table? then why not using a map data structure?
it provides you the pair location-distance
Why not construct directly a TreeMap with the distance as the key and the name as the value. That way they will always be kept sorted by distance.
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Kent
TreeMap with distance as key is good idea, but what if there are 5 entries with same distance?
Presumably you have some class that contains the latitude, longitude and location name. You could put objects of this class into a TreeSet, where the comparator has the current location as constructor arguments, and calculates the distances to do the comparison.
answered Jan 20, 2012 at 11:18
Dawood ibn Kareem
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use Arrays.sort(). You can dont even have to add the distance of each one from current in a separate array. just implement the comparator correctly.
use this after doing a toArray() on your ArrayList.
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John B
The point of the question was how to associate an array of names to an array of distances (that has been sorted).