get closest value to a number in array

Question

I have an array of positive/negative ints

int[] numbers = new int[10];
numbers[0] = 100;
numbers[1] = -34200;
numbers[2] = 3040;
numbers[3] = 400433;
numbers         


        

Answer 1

public int getClosestToTarget(int target, int[] values) {

    if (values.length < 1)
        throw new IllegalArgumentException("The values should be at least one element");
    if (values.length == 1) {
        return values[0];
    }
    int closestValue = values[0];
    int leastDistance = Math.abs(values[0] - target);
    for (int i = 0; i < values.length; i++) {
        int currentDistance = Math.abs(values[i] - target);
        if (currentDistance < leastDistance) {
            closestValue = values[i];
            leastDistance = currentDistance;
        }
    }
    return closestValue;
}

Answer 2

you are very close. I think the initial value of 'distance' should be a big number instead of 0. And use the absolute value for the cdistance.

Answer 3

Kotlin is so helpful

fun List<Int>.closestValue(value: Int) = minBy { abs(value - it) }

val values = listOf(1, 8, 4, -6)

println(values.closestValue(-7)) // -6
println(values.closestValue(2)) // 1
println(values.closestValue(7)) // 8

List doesn't need to be sorted BTW

Answer 4

public class Main    
{
    public static void main(String[] args)
    {   
        int[] numbers = {6,5,10,1,3,4,2,14,11,12};

        for(int i =0; i<numbers.length; i++)
        {
            sum(numbers, i, numbers[i], 12, String.valueOf(numbers[i]));
        }
    }

    static void sum(int[] arr, int i, int sum, int target, String s)
    {

        int flag = 0;

        for(int j = i+1; j<arr.length; j++)
        {

            if(arr[i] == target && flag==0)
            {
                System.out.println(String.valueOf(arr[i]));
                flag =1;

            }
            else if(sum+arr[j] == target)
            { 
                System.out.println(s+" "+String.valueOf(arr[j]));

            }
            else
            {
                sum(arr, j, sum+arr[j], target, s+" "+String.valueOf(arr[j]));
            }
        }        
    }
}

Answer 5

int valueToFind = 490;

Map<Integer, Integer> map = new HashMap();

for (int i = 0, i < numbers.length; i++){
    map.put(Math.abs(numbers[i] - valueToFind), numbers[i]);
}

List<Integer> keys = new ArrayList(map.keySet());
Collections.sort(keys);

return map.get(keys.get(0));

Answer 6

In Java 8:

List<Integer> list = Arrays.stream(numbers).boxed().collect(Collectors.toList());

int n = 490;

int c = list.stream()
            .min(Comparator.comparingInt(i -> Math.abs(i - n)))
            .orElseThrow(() -> new NoSuchElementException("No value present"));

Initially, you can use a List instead of an Array (lists have much more functionality).