README.md

Assignment11

The sum factor of an array is defined to be the number of times that the sum of the array appears as an element of the array.

Write a function named sumFactor that returns the sum factor of its array argument.

Examples

• the sum factor of {1, -1, 1, -1, 1, -1, 1} is 4 because the sum of the elements of the array is 1 and 1 appears four times in the array
• the sum factor of {1, 2, 3, 4} is 0 because the sum of the elements of the array is 10 and 10 does not occur as an element of the array
• the sum factor of the empty array {} is defined to be 0

The function signature is int sumFactor(int[] a)

if a is	return	reason
{3, 0, 2, -5, 0}	2	the sum of array is 0 and 0 occurs 2 times
{9, -3, -3, -1, -1}	0	the sum of the array is 1 and 1 does not occur in array
{1}	1	the sum of the array is 1 and 1 occurs once in the array
{0, 0, 0}	3	the sum of the array is 0 and 0 occurs 3 times in the array

Solution

public class Assignment11 {
  public static void main(String[] args) {
    int result = sumFactor(new int[]{3, 0, 2, -5, 0});
    System.out.println(result);

    result = sumFactor(new int[]{9, -3, -3, -1, -1});
    System.out.println(result);

    result = sumFactor(new int[]{1});
    System.out.println(result);

    result = sumFactor(new int[]{0, 0, 0});
    System.out.println(result);
  }

  static int sumFactor(int[] a) {
    int sum = 0;
    for (int i = 0; i < a.length; i++) {
      sum += a[i];
    }

    int sumFactor = 0;
    for (int i = 0; i < a.length; i++) {
      if (sum == a[i]) {
        sumFactor++;
      }
    }

    return sumFactor;
  }
}