Plausible Stack Story
Values 1..N are pushed onto a stack in the given push order; pops may happen at any time. Could the given pop order have occurred?
Input: the first line has N; the second line has the push order; the third line has the claimed pop order.
Output: YES or NO.
Constraints:
- 1 ≤ N ≤ 105
- both lines are permutations of 1..N
Sample Tests
Input 1
5 1 2 3 4 5 4 5 3 2 1
Output 1
YES
Input 2
3 1 2 3 3 1 2
Output 2
NO
Discussion (opens after you solve — no spoilers before)
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