# 1013. Partition Array Into Three Parts With Equal Sum

<https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum>

## Description

Given an array of integers `arr`, return `true` if we can partition the array into three **non-empty** parts with equal sums.

Formally, we can partition the array if we can find indexes `i + 1 < j` with `(arr[0] + arr[1] + ... + arr[i] == arr[i + 1] + arr[i + 2] + ... + arr[j - 1] == arr[j] + arr[j + 1] + ... + arr[arr.length - 1])`

**Example 1:**

```
**Input:** arr = [0,2,1,-6,6,-7,9,1,2,0,1]
**Output:** true
**Explanation:** 0 + 2 + 1 = -6 + 6 - 7 + 9 + 1 = 2 + 0 + 1
```

**Example 2:**

```
**Input:** arr = [0,2,1,-6,6,7,9,-1,2,0,1]
**Output:** false
```

**Example 3:**

```
**Input:** arr = [3,3,6,5,-2,2,5,1,-9,4]
**Output:** true
**Explanation:** 3 + 3 = 6 = 5 - 2 + 2 + 5 + 1 - 9 + 4
```

**Constraints:**

* `3 <= arr.length <= 5 * 104`
* `-104 <= arr[i] <= 104`

## ac

```java
```