Given two sequences pushed and popped with distinct values, return true if and only if this could have been the result of a sequence of push and pop operations on an initially empty stack.

Example 1:

Input: pushed= [1,2,3,4,5], popped= [4,5,3,2,1] Output: true Explanation: Wemightdothefollowingsequence: 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: 1cannotbepoppedbefore2.

Note:

1. 0 <= pushed.length == popped.length <= 1000
2. 0 <= pushed[i], popped[i] < 1000
3. pushed is a permutation of popped.
4. pushed and popped have distinct values.

给 2 个数组，一个数组里面代表的是 push 的顺序，另一个数组里面代表的是 pop 的顺序。问按照这样的顺序操作以后，最终能否把栈清空？

这一题也是靠栈操作的题目，按照 push 数组的顺序先把压栈，然后再依次在 pop 里面找栈顶元素，找到了就 pop，直到遍历完 pop 数组，最终如果遍历完了 pop 数组，就代表清空了整个栈了。