- Time limit: 1.00 s
- Memory limit: 512 MB
You are given an input list that consists of n numbers. Each integer between 1 and n appears exactly once in the list.
Your task is to create a sorted output list using two stacks. On each move you can do one of the following:
- Move the first number from the input list to a stack
- Move a number from a stack to the end of the output list
The first input line has an integer n.
The second line has n integers: the contents of the input list.
Print n integers: for each number the stack where it is moved (1 or 2).
You can print any valid solution. If there are no solutions, print "IMPOSSIBLE".
- 1 \le n \le 2 \cdot 10^5
5 2 3 1 5 4
1 2 1 1 2