Untitled

import java.util.ArrayList;
import java.util.List;

class Result {

    public static int reductionCost(List<Integer> num) {
        int a[] = num.stream().mapToInt(Integer::intValue).toArray();
        int i = 0;
        int j = a.length - 1;
        return minCost(a, i, j);
    }
    private static int minCost(int a[], int i,
                              int j)
    {
        if (i >= j) {
            return 0;
        }
        int best_cost = Integer.MAX_VALUE;
        for (int pos = i; pos < j; pos++) {
            int left = minCost(a, i, pos);
            int right = minCost(a, pos + 1, j);
            best_cost = Math.min(
                    best_cost,
                    left + right + combine(a, i, j));
        }
        return best_cost;
    }

    private static int combine(int a[], int i, int j)
    {
        int sum = 0;
        for (int l = i; l <= j; l++)
            sum += a[l];
        return sum;
    }
}