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# 1151. Minimum Swaps to Group All 1's Together

<https://leetcode.com/problems/minimum-swaps-to-group-all-1s-together>

## Description

Given a binary array `data`, return the minimum number of swaps required to group all `1`’s present in the array together in **any place** in the array.

**Example 1:**

```
**Input:** data = [1,0,1,0,1]
**Output:** 1
**Explanation:** 
There are 3 ways to group all 1's together:
[1,1,1,0,0] using 1 swap.
[0,1,1,1,0] using 2 swaps.
[0,0,1,1,1] using 1 swap.
The minimum is 1.
```

**Example 2:**

```
**Input:** data = [0,0,0,1,0]
**Output:** 0
**Explanation:** 
Since there is only one 1 in the array, no swaps needed.
```

**Example 3:**

```
**Input:** data = [1,0,1,0,1,0,0,1,1,0,1]
**Output:** 3
**Explanation:** 
One possible solution that uses 3 swaps is [0,0,0,0,0,1,1,1,1,1,1].
```

**Example 4:**

```
**Input:** data = [1,0,1,0,1,0,1,1,1,0,1,0,0,1,1,1,0,0,1,1,1,0,1,0,1,1,0,0,0,1,1,1,1,0,0,1]
**Output:** 8
```

**Constraints:**

* `1 <= data.length <= 105`
* `data[i]` is `0` or `1`.

## ac

```java
```