sumIsPower

Question :

Write a function sumIsPower with signatuare

boolean sumIsPower(int[] arr)                      

which outputs true if the sum of the elements in the input array arr is a power of 2, false otherwise. Recall that the powers of 2 are 1, 2, 4, 8, 16, and so on. In general a number is a power of 2 if and only if it is of the form 2ⁿ for some nonnegative integer n. You may assume (without verifying in your code) that all elements in the array are positive integers. If the input array arr is null, the return value should be false.

Examples:  sumIsPower({8,8,8,8}) is true since 8 + 8 + 8 + 8 = 32 = 2⁵.  sumIsPower({8,8,8})  is false, since 8 + 8 +8 = 24, not a power of 2.

Solution :

public static bool sumIsPower(int[] arr)

        {

            int power = 2, sum = 0;

            for (int i = 0; i < arr.Length; i++)

            {

                sum += arr[i];

                power *= 2;

            }

            if (sum == power)

                return true;

            else

                return false;

        }