class Solution {
    public boolean canThreePartsEqualSum(int[] arr) {

        int n = 3;

        if (arr.length <= 0) {
            return false;
        }

        if (isThreeMultiple(arr, n)) {
            int average = getAverage(arr, n);
            return isDivideThreePart(arr, average, n);
        }else {
            return false;
        }

    }

    /**
     * 判断是否是n的倍数
     */
    public boolean isThreeMultiple(int[] arr, int n) {
        int sum = 0;
        for (int i = 0; i < arr.length; i++) {
            sum += arr[i];
        }

        if (sum%n == 0) {
            return true;
        }else {
            return false;
        }
    }

    /**
     * 获取平均值
     */
    public int getAverage(int[] arr, int n) {
        int sum = 0;

        for (int i = 0; i < arr.length; i++) {
            sum += arr[i];
        }

        return sum/n;
    }

    /**
     * 判断数组是否可以分为n部分
     */
    public boolean isDivideThreePart(int[] arr, int average, int n) {
        int flag = 0;
        int sum = 0;
        for(int i = 0; i < arr.length; i++) {
            sum += arr[i];
            if (sum == average) {
                flag++;
                sum = 0;
            }
        }

        return flag >= n;
    }

}