src/main/java/com/fishercoder/solutions/_548.java

package com.fishercoder.solutions;

import java.util.HashSet;
import java.util.Set;

public class _548 {

    public static class Solution1 {
        public boolean splitArray(int[] nums) {
            int len = nums.length;
            if (len < 7) {
                return false;
            }
            int[] sum = new int[len];
            sum[0] = nums[0];
            for (int i = 1; i < len; i++) {
                sum[i] = sum[i - 1] + nums[i];
            }
            for (int j = 3; j < len - 3; j++) {
                Set<Integer> set = new HashSet<>();
                for (int i = 1; i < j - 1; i++) {
                    if (sum[i - 1] == sum[j - 1] - sum[i]) {
                        /**this is sum(0, i-1) and sum(i+1, j-1)*/
                        set.add(sum[i - 1]);
                    }
                }
                for (int k = j + 2; k < len - 1; k++) {
                    if (sum[k - 1] - sum[j] == sum[len - 1] - sum[k] && set.contains(sum[k - 1] - sum[j])) {
                        /**this is sum(j+1, k-1) and sum(k+1, len-1)*/
                        return true;
                    }
                }
            }
            return false;
        }
    }

}