946 - Validate Stack Sequences.

Medium

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.