PERMUT2 - Ambiguous Permutations


Some programming contest problems are really tricky: not only do they require a different output format from what you might have expected, but also the sample output does not show the difference. For an example, let us look at permutations.
A permutation of the integers 1 to n is an ordering of these integers. So the natural way to represent a permutation is to list the integers in this order. With n = 5, a permutation might look like 2, 3, 4, 5, 1.
However, there is another possibility of representing a permutation: You create a list of numbers where the i-th number is the position of the integer i in the permutation. Let us call this second possibility an inverse permutation. The inverse permutation for the sequence above is 5, 1, 2, 3, 4.
An ambiguous permutation is a permutation which cannot be distinguished from its inverse permutation. The permutation 1, 4, 3, 2 for example is ambiguous, because its inverse permutation is the same. To get rid of such annoying sample test cases, you have to write a program which detects if a given permutation is ambiguous or not.

Input Specification

The input contains several test cases.
The first line of each test case contains an integer n (1 ≤ n ≤ 100000). Then a permutation of the integers 1 to n follows in the next line. There is exactly one space character between consecutive integers. You can assume that every integer between 1 and n appears exactly once in the permutation.
The last test case is followed by a zero.

Output Specification

For each test case output whether the permutation is ambiguous or not. Adhere to the format shown in the sample output.

Sample Input

4
1 4 3 2
5
2 3 4 5 1
1
1
0

Sample Output

ambiguous
not ambiguous
ambiguous

hide comments
ramesh_961: 2017-05-26 08:52:59

Easy! AC in one go!

vishalshrm539: 2017-04-04 20:55:43

AC in one go !

amulyagaur: 2017-03-13 17:54:08

AC in 0.03 s .........how to get 0.00s??whats the approach??

vanvinhbk94: 2017-02-18 06:04:10

AC in one go ^^

rohit9934: 2017-02-12 16:32:05

IF YOU ARE STRUGGLING TO UNDERSTAND
Inverse permutation is nothing but position of the element in the array,for eg In 1st TC. Position of 1 is 5th,position of 5 is 4th.

sudiptob2: 2017-02-09 13:13:05

name should be ambiguous description :P

prageet_8112: 2017-02-05 21:26:40

AC in one go!!

ayushagg31: 2017-01-27 07:09:21

ambiguos costed me 2WA!!!

shantanu_sarin: 2017-01-01 14:49:55

irritating lang

kass_97: 2016-12-31 12:47:14

Unclear problem statement, still AC in 2nd go.....my 100th yeahh


Added by:Adrian Kuegel
Date:2005-06-24
Time limit:10s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: NODEJS PERL6 VB.NET
Resource:own problem, used in University of Ulm Local Contest 2005