TapeEquilibrium - Codility

TapeEquilibrium.java

// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
        int size = A.length;
        int[] presum = new int[size];
        presum[size - 1] = A[size - 1];
        for (int i = A.length - 2; i >= 0; i --) {
            presum[i] = presum[i + 1] + A[i];
        }
        // 
        int ans = Integer.MAX_VALUE;
        int leftSum = A[0];
        for (int i = 1; i < A.length; i ++) {
            int diff = Math.abs(leftSum - presum[i]);
            ans = Math.min(ans, diff);
            leftSum += A[i];
        }
        return ans;
    }
}