548.Split Array with Equal Sum

https://leetcode.com/problems/split-array-with-equal-sum/discuss/101481/Simple-Java-solution-O(n2\

class Solution {
    public boolean splitArray(int[] nums) {
        int n = nums.length;
        if(n < 7)
            return false;
        int[] sum = new int[n];
        sum[0] = nums[0];
        for(int i = 1; i < n; i++){
            sum[i] = sum[i - 1] + nums[i];
        }
        for(int j = 3; j < n - 3; j++){
            Set<Integer> set = new HashSet<>();
            for(int i = 1; i < j - 1; i++){
                if(sum[i - 1] == sum[j - 1] - sum[i])
                    set.add(sum[i - 1]);
            }
            for(int k = j + 2; k < n - 1; k++){
                if((sum[k - 1] - sum[j] == sum[n - 1] - sum[k]) && set.contains(sum[n -1] - sum[k])){
                    return true;
                }
            }
        }

        return false;
    }
}