> For the complete documentation index, see [llms.txt](https://jaywin.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jaywin.gitbook.io/leetcode/solutions/1564-put-boxes-into-the-warehouse-i.md).

# 1564. Put Boxes Into the Warehouse I

<https://leetcode.com/problems/put-boxes-into-the-warehouse-i>

## Description

You are given two arrays of positive integers, `boxes` and `warehouse`, representing the heights of some boxes of unit width and the heights of `n` rooms in a warehouse respectively. The warehouse's rooms are labelled from `0` to `n - 1` from left to right where `warehouse[i]` (0-indexed) is the height of the `ith` room.

Boxes are put into the warehouse by the following rules:

* Boxes cannot be stacked.
* You can rearrange the insertion order of the boxes.
* Boxes can only be pushed into the warehouse from left to right only.
* If the height of some room in the warehouse is less than the height of a box, then that box and all other boxes behind it will be stopped before that room.

Return *the maximum number of boxes you can put into the warehouse.*

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/08/26/11.png)

```
**Input:** boxes = [4,3,4,1], warehouse = [5,3,3,4,1]
**Output:** 3
**Explanation:**![](https://assets.leetcode.com/uploads/2020/08/26/12.png)
We can first put the box of height 1 in room 4. Then we can put the box of height 3 in either of the 3 rooms 1, 2, or 3. Lastly, we can put one box of height 4 in room 0.
There is no way we can fit all 4 boxes in the warehouse.
```

**Example 2:**

![](https://assets.leetcode.com/uploads/2020/08/26/21.png)

```
**Input:** boxes = [1,2,2,3,4], warehouse = [3,4,1,2]
**Output:** 3
**Explanation: 
![](https://assets.leetcode.com/uploads/2020/08/26/22.png)**Notice that it's not possible to put the box of height 4 into the warehouse since it cannot pass the first room of height 3.
Also, for the last two rooms, 2 and 3, only boxes of height 1 can fit.
We can fit 3 boxes maximum as shown above. The yellow box can also be put in room 2 instead.
Swapping the orange and green boxes is also valid, or swapping one of them with the red box.
```

**Example 3:**

```
**Input:** boxes = [1,2,3], warehouse = [1,2,3,4]
**Output:** 1
**Explanation:** Since the first room in the warehouse is of height 1, we can only put boxes of height 1.
```

**Example 4:**

```
**Input:** boxes = [4,5,6], warehouse = [3,3,3,3,3]
**Output:** 0
```

**Constraints:**

* `n == warehouse.length`
* `1 <= boxes.length, warehouse.length <= 10^5`
* `1 <= boxes[i], warehouse[i] <= 10^9`

## ac

```java
```