Score : $200$ points
Evi has $N$ integers $a_1,a_2,..,a_N$. His objective is to have $N$ equal integers by transforming some of them.
He may transform each integer at most once. Transforming an integer $x$ into another integer $y$ costs him $(x-y)^2$ dollars. Even if $a_i=a_j (i≠j)$, he has to pay the cost separately for transforming each of them (See Sample 2).
Find the minimum total cost to achieve his objective.
The input is given from Standard Input in the following format:
$N$ $a_1$ $a_2$ ... $a_N$
Print the minimum total cost to achieve Evi's objective.
2 4 8
8
Transforming the both into $6$s will cost $(4-6)^2+(8-6)^2=8$ dollars, which is the minimum.
3 1 1 3
3
Transforming the all into $2$s will cost $(1-2)^2+(1-2)^2+(3-2)^2=3$ dollars. Note that Evi has to pay $(1-2)^2$ dollar separately for transforming each of the two $1$s.
3 4 2 5
5
Leaving the $4$ as it is and transforming the $2$ and the $5$ into $4$s will achieve the total cost of $(2-4)^2+(5-4)^2=5$ dollars, which is the minimum.
4 -100 -100 -100 -100
0
Without transforming anything, Evi's objective is already achieved. Thus, the necessary cost is $0$.