Trying to write a program that takes a set of doubles and then sorts these values into different arrays based on their tenths and hundredths places after the decimal. So for an array [1.25, 2.25, 3.5, 10.5, 7.75, 4.75] sort the .25's .5's .75's into separate arrays so that calculations may be done.

CodePudding user response：

You use the term 'sort' but I think you are really talking about grouping the values into collections based on their first 2 decimal values. If that's correct then you can use:

values.stream().collect(Collectors.groupingBy(v -> (int)(v % 1 * 100));

This will generate a map from each fraction (expressed as a /100 int) to a list of values that have that fraction. If you particularly need arrays you can use .toArray().

CodePudding user response：

My solution is a little grouping algorithm:

public static List<List<Float>> getSortedArrays(float[] array){
    List<List<Float>> result = new ArrayList<>();
    HashMap<Float, Integer> createdArrays= new HashMap<>();
    for (float f : array) {
        float ending = f-((int)f);
        if(createdArrays.containsKey(ending)){
            result.get(createdArrays.get(ending)).add(f);
        }else{
            createdArrays.put(ending, result.size());
            List<Float> newList = new ArrayList<>();
            newList.add(f);
            result.add(newList);
        }
    }
    return result;
}

I am basically looping through the float array and with this trick float ending = f-((int)f); I am separating just the numbers after the decimal. Than I am checking if there is already created array for that ending, if yes I add currently processed float, if not I create it and also add that float there. HashMap is there to keep track of already created Arrays.

Again use .toArray() if you need array...