Score : $600$ points
We have a set $S$ of $N$ points in a two-dimensional plane. The coordinates of the $i$-th point are $(x_i, y_i)$. The $N$ points have distinct $x$-coordinates and distinct $y$-coordinates.
For a non-empty subset $T$ of $S$, let $f(T)$ be the number of points contained in the smallest rectangle, whose sides are parallel to the coordinate axes, that contains all the points in $T$. More formally, we define $f(T)$ as follows:
Find the sum of $f(T)$ over all non-empty subset $T$ of $S$. Since it can be enormous, print the sum modulo $998244353$.
Input is given from Standard Input in the following format:
$N$ $x_1$ $y_1$ $:$ $x_N$ $y_N$
Print the sum of $f(T)$ over all non-empty subset $T$ of $S$, modulo $998244353$.
3 -1 3 2 1 3 -2
13
Let the first, second, and third points be $P_1$, $P_2$, and $P_3$, respectively. $S = \{P_1, P_2, P_3\}$ has seven non-empty subsets, and $f$ has the following values for each of them:
The sum of these is $13$.
4 1 4 2 1 3 3 4 2
34
10 19 -11 -3 -12 5 3 3 -15 8 -14 -9 -20 10 -9 0 2 -7 17 6 -6
7222
Be sure to print the sum modulo $998244353$.