# 0930. Binary Subarrays With Sum

<https://leetcode.com/problems/binary-subarrays-with-sum>

## Description

Given a binary array `nums` and an integer `goal`, return *the number of non-empty **subarrays** with a sum* `goal`.

A **subarray** is a contiguous part of the array.

**Example 1:**

```

**Input:** nums = [1,0,1,0,1], goal = 2
**Output:** 4
**Explanation:** The 4 subarrays are bolded and underlined below:
[**1,0,1**,0,1]
[**1,0,1,0**,1]
[1,**0,1,0,1**]
[1,0,**1,0,1**]
```

**Example 2:**

```

**Input:** nums = [0,0,0,0,0], goal = 0
**Output:** 15
```

**Constraints:**

* `1 <= nums.length <= 3 * 104`
* `nums[i]` is either `0` or `1`.
* `0 <= goal <= nums.length`

## ac

```java
```