Given a permutation check if it is an ambiguous permutation. Solution for https://www.codechef.com/problems/PERMUT2

ambiguous_permutation.cpp

#include <iostream>
#include <vector>
using namespace std;

bool isAmbiguous(vector<int>& arr)
{
    int i;
    vector<int> inverse(arr.size());
    for( i = 0; i < arr.size(); i++ )
    {
        inverse[arr[i]-1] = i+1;
    }
    for( i = 0; i < arr.size(); i++ )
    {
        if( arr[i] != inverse[i] )
            return false;
    }
    return true;
}

int main() 
{
	int n;
	while(true)
	{
	    cin >> n;
	    if( n > 0 )
	    {
	        vector<int> arr(n);
	        int i;
	        for( i = 0; i < n; i++ )
	        {
	            cin >> arr[i];
	        }
	        if( isAmbiguous(arr) )
	        {
	            cout << "ambiguous" << endl;
	        }
	        else
	        {
	            cout << "not ambiguous" << endl;
	        }
	    }
	    else
	        break;
	}
	return 0;
}