100% solution to codility sample test in java - https://codility.com/demo/take-sample-test/

gistfile1.txt

class Solution {
    public int solution(int[] A) {
        int N = A.length;
        double sum = 0;
        for (double i : A) {
            sum += i;
        }

        if (N == 1) return 0;
        double left = 0;
        double right = sum;
        for (int i = 0; i < N; i++) {
            left = i == 0 ? 0 : left + A[i - 1];
            right = right - A[i];
            if (left == right) {
                return i;
            }
        }
        return -1;
    }
}