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.
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.
For each test case output whether the permutation is ambiguous or not. Adhere to the format shown in the sample output.
4 1 4 3 2 5 2 3 4 5 1 1 1 0
ambiguous not ambiguous ambiguous
For those who are having a hard time to understand the problem.
Take care of the sentence, "where the i-th number is the position of the integer i in the permutation" . Read it by considering the above examples mentioned in the question.
is 1,2,3,4 is ambigous or not?
AC after 4 hours:Happy Ending::
Can i get the corner cases for this.
Ac in one go!
always see people bragging about ac in one go but that just means they don't solve hard enough problems
AC in one go!
ac in one go!!!
ac in one go