# 0974. Subarray Sums Divisible by K

<https://leetcode.com/problems/subarray-sums-divisible-by-k>

## Description

Given an integer array `nums` and an integer `k`, return *the number of non-empty **subarrays** that have a sum divisible by* `k`.

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

**Example 1:**

```
**Input:** nums = [4,5,0,-2,-3,1], k = 5
**Output:** 7
**Explanation:** There are 7 subarrays with a sum divisible by k = 5:
[4, 5, 0, -2, -3, 1], [5], [5, 0], [5, 0, -2, -3], [0], [0, -2, -3], [-2, -3]
```

**Example 2:**

```
**Input:** nums = [5], k = 9
**Output:** 0
```

**Constraints:**

* `1 <= nums.length <= 3 * 104`
* `-104 <= nums[i] <= 104`
* `2 <= k <= 104`

## ac

```java
```
