We call polynomials $A(x) = a_n x^n +. . .+a_1 x+a_0$ and $B(x) = b_m x^m +. . .+b_1 x+b_0$
($a_n b_m \neq 0$) similar if the following conditions hold:
$(i)$ $n = m$;
$(ii)$ There is a permutation $\pi$ of the set $\{ 0, 1, . . . , n\} $ such that $b_i = a_{\pi (i)}$ for each $i \in {0, 1, . . . , n}$.
Let $P(x)$ and $Q(x)$ be similar polynomials with integer coefficients. Given that
$P(16) = 3^{2012}$, find the smallest possible value of $|Q(3^{2012})|$.

[i]Proposed by Milos Milosavljevic[/i]
Given that \( P(x) = a_n x^n + \ldots + a_1 x + a_0 \) and \( Q(x) = b_n x^n + \ldots + b_1 x + b_0 \) are similar polynomials, we know:
1. \( n = m \)
2. There exists a permutation \(\pi\) of the set \(\{0, 1, \ldots, n\}\) such that \( b_i = a_{\pi(i)} \) for each \( i \in \{0, 1, \ldots, n\} \).

Given \( P(16) = 3^{2012} \), we need to find the smallest possible value of \( |Q(3^{2012})| \).

First, we note that since \( P(x) \) and \( Q(x) \) are similar, their coefficients are permutations of each other. This implies that \( Q(x) \) can be written as \( Q(x) = a_{\pi(n)} x^n + \ldots + a_{\pi(1)} x + a_{\pi(0)} \).

We start by considering the congruence properties modulo 5:
\[
3^{2012} \equiv 1 \pmod{5}
\]
Thus,
\[
Q(3^{2012}) \equiv Q(1) \pmod{5}
\]
Since \( Q(x) \) is a permutation of the coefficients of \( P(x) \), we have:
\[
Q(1) = P(1)
\]
Given \( P(16) = 3^{2012} \), we need to find \( P(1) \mod 5 \):
\[
P(1) = a_n + a_{n-1} + \ldots + a_1 + a_0
\]
Since \( 3^{2012} \equiv 1 \pmod{5} \), we have:
\[
P(16) \equiv 1 \pmod{5}
\]
Thus,
\[
P(1) \equiv 1 \pmod{5}
\]
Therefore,
\[
Q(3^{2012}) \equiv 1 \pmod{5}
\]
This implies that \( |Q(3^{2012})| \geq 1 \).

Next, we consider the specific form of \( P(x) \) and \( Q(x) \). Suppose \( P(x) = ax^2 + bx + c \) and \( Q(x) = cx^2 + ax + b \). We are given:
\[
P(16) = a \cdot 16^2 + b \cdot 16 + c = 3^{2012}
\]
We need to find \( Q(3^{2012}) \):
\[
Q(3^{2012}) = c \cdot (3^{2012})^2 + a \cdot 3^{2012} + b
\]
Substituting \( c = 3^{2012} - a \cdot 16^2 - b \cdot 16 \) into the equation for \( Q(3^{2012}) \):
\[
Q(3^{2012}) = (3^{2012} - a \cdot 16^2 - b \cdot 16) \cdot (3^{2012})^2 + a \cdot 3^{2012} + b
\]
Simplifying, we get:
\[
Q(3^{2012}) = 3^{2012} \cdot (3^{2012})^2 - a \cdot 16^2 \cdot (3^{2012})^2 - b \cdot 16 \cdot (3^{2012})^2 + a \cdot 3^{2012} + b
\]
\[
= 3^{4024} - a \cdot 16^2 \cdot 3^{4024} - b \cdot 16 \cdot 3^{4024} + a \cdot 3^{2012} + b
\]
Since \( 3^{4024} \) is very large, the dominant term is \( 3^{4024} \). The smallest possible value of \( |Q(3^{2012})| \) is thus determined by the smallest non-zero value modulo 5, which is 1.

The final answer is \( \boxed{1} \).