Solution for the TapeEquilibrium test at https://codility.com/demo/take-sample-test/tape_equilibrium

Solution.java

/**
 * Created by edouard on 14/06/18.
 */
class Solution {
    public int solution(int[] A) {
        int maxIndex = A.length - 1;
        int[] leftSum = new int[A.length];
        leftSum[0] = A[0];
        for (int i = 1; i < A.length; i++) {
            leftSum[i] = A[i] + leftSum[i - 1];
        }
        int[] rightSum = new int[A.length];
        rightSum[maxIndex] = A[maxIndex];
        for (int i = A.length - 2; i >= 0; i--) {
            rightSum[i] = A[i] + rightSum[i + 1];
        }
        int minDiff = Integer.MAX_VALUE;
        for (int i = 1; i < A.length; i++) {
            minDiff = Math.min(minDiff, Math.max(rightSum[i], leftSum[i - 1]) - Math.min(rightSum[i], leftSum[i - 1]));
        }
        return minDiff;
    }
}