# 0946. Validate Stack Sequences

https://leetcode.com/problems/validate-stack-sequences

## Description

Given two integer arrays `pushed` and `popped` each with distinct values, return `true` _if this could have been the result of a sequence of push and pop operations on an initially empty stack, or_ `false` _otherwise._

**Example 1:**

```
**Input:** pushed = [1,2,3,4,5], popped = [4,5,3,2,1]
**Output:** true
**Explanation:** We might do the following sequence:
push(1), push(2), push(3), push(4),
pop() -> 4,
push(5),
pop() -> 5, pop() -> 3, pop() -> 2, pop() -> 1
```

**Example 2:**

```
**Input:** pushed = [1,2,3,4,5], popped = [4,3,5,1,2]
**Output:** false
**Explanation:** 1 cannot be popped before 2.
```

**Constraints:**

* `1 <= pushed.length <= 1000`
* `0 <= pushed[i] <= 1000`
* All the elements of `pushed` are **unique**.
* `popped.length == pushed.length`
* `popped` is a permutation of `pushed`.

## ac

```java
```
