Sum of 'n' Numbers sum_of_n (or SequenceSum.sumOfN in Java, SequenceSum.SumOfN in C#) takes an integer n and returns a List (an Array in Java/C#) of length abs(n) + 1. The List/Array contains the numbers in the arithmetic series produced by taking the sum of the consecutive integer numbers from 0 to n inclusive. n can also be 0 or a negative val…

SumofnNumbers.java

public class SequenceSum {
	public static int[] sumOfN(int n) {
    boolean isNegative = n < 0;
    int arraySize = Math.abs(n)+1; 
    int[] result= new int[arraySize];
    for(int i = 1; i < arraySize;i++){
      result[i] = isNegative? result[i-1] - i: result[i-1] + i;
    }
    return result;
  }
}