Problem:
Score : 600 points

Problem Statement

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:

f(T) := (the number of integers i (1 \leq i \leq N) such that a \leq x_i \leq b and c \leq y_i \leq d, where a, b, c, and d are the minimum x-coordinate, the maximum x-coordinate, the minimum y-coordinate, and the maximum y-coordinate of the points in T)

Find the sum of f(T) over all non-empty subset T of S. Since it can be enormous, print the sum modulo 998244353.

Constraints

1 \leq N \leq 2 \times 10^5

-10^9 \leq x_i, y_i \leq 10^9

x_i \neq x_j (i \neq j)

y_i \neq y_j (i \neq j)

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
x_1 y_1
:
x_N y_N

Output

Print the sum of f(T) over all non-empty subset T of S, modulo 998244353.

Sample Input 1

3
-1 3
2 1
3 -2

Sample Output 1

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:

f(\{P_1\}) = 1

f(\{P_2\}) = 1

f(\{P_3\}) = 1

f(\{P_1, P_2\}) = 2

f(\{P_2, P_3\}) = 2

f(\{P_3, P_1\}) = 3

f(\{P_1, P_2, P_3\}) = 3

The sum of these is 13.

Sample Input 2

4
1 4
2 1
3 3
4 2

Sample Output 2

34

Sample Input 3

10
19 -11
-3 -12
5 3
3 -15
8 -14
-9 -20
10 -9
0 2
-7 17
6 -6

Sample Output 3

7222

Be sure to print the sum modulo 998244353.

Solution in Common Lisp (SBCL 1.1.14) (judge verdict: Accepted)

;; -*- coding: utf-8 -*-
(eval-when (:compile-toplevel :load-toplevel :execute)
  (defparameter OPT
    #+swank '(optimize (speed 3) (safety 2))
    #-swank '(optimize (speed 3) (safety 0) (debug 0)))
  #+swank (ql:quickload '(:cl-debug-print :fiveam))
  #-swank (set-dispatch-macro-character #\# #\> (lambda (s c p) (declare (ignore c p)) (read s nil (values) t))))
#+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax)
#-swank (disable-debugger) ; for CS Academy

;; BEGIN_INSERTED_CONTENTS
;; Treap accessible by index (O(log(n))).
;; Virtually it works like std::set of C++ or TreeSet of Java. 

;; Note:
;; - You shouldn't insert duplicate keys into a treap unless you know what you
;; are doing.
;; - You cannot rely on the side effect when you call any destructive operations
;; on a treap. Always use the returned value.
;; - An empty treap is NIL.

(defstruct (treap (:constructor %make-treap (key priority &key left right (count 1)))
                  (:copier nil)
                  (:conc-name %treap-))
  (key 0 :type fixnum)
  (priority 0 :type (integer 0 #.most-positive-fixnum))
  (count 0 :type (integer 0 #.most-positive-fixnum))
  (left nil :type (or null treap))
  (right nil :type (or null treap)))

(declaim (inline treap-count))
(defun treap-count (treap)
  "Returns the size of the (nullable) TREAP."
  (declare ((or null treap) treap))
  (if (null treap)
      0
      (%treap-count treap)))

(declaim (inline update-count))
(defun update-count (treap)
  (declare (treap treap))
  (setf (%treap-count treap)
        (+ 1
           (treap-count (%treap-left treap))
           (treap-count (%treap-right treap)))))

(declaim (inline treap-bisect-left)
         (ftype (function * (values (integer 0 #.most-positive-fixnum) t &optional)) treap-bisect-left))
(defun treap-bisect-left (value treap &key (order #'<))
  "Returns the smallest index and the corresponding key that satisfies
TREAP[index] >= VALUE. Returns the size of TREAP and VALUE if TREAP[size-1] <
VALUE."
  (declare (function order))
  (labels ((recur (count treap)
             (declare ((integer 0 #.most-positive-fixnum) count))
             (cond ((null treap) (values nil nil))
                   ((funcall order (%treap-key treap) value)
                    (recur count (%treap-right treap)))
                   (t (let ((left-count (- count (treap-count (%treap-right treap)) 1)))
                        (multiple-value-bind (idx key)
                            (recur left-count (%treap-left treap))
                          (if idx
                              (values idx key)
                              (values left-count (%treap-key treap)))))))))
    (declare (ftype (function * (values t t &optional)) recur))
    (multiple-value-bind (idx key)
        (recur (treap-count treap) treap)
      (if idx
          (values idx key)
          (values (treap-count treap) value)))))

(declaim (inline treap-split)
         (ftype (function * (values (or null treap) (or null treap) &optional)) treap-split))
(defun treap-split (key treap &key (order #'<))
  "Destructively splits the TREAP with reference to KEY and returns two treaps,
the smaller sub-treap (< KEY) and the larger one (>= KEY)."
  (declare (function order)
           ((or null treap) treap))
  (labels ((recur (treap)
             (cond ((null treap)
                    (values nil nil))
                   ((funcall order (%treap-key treap) key)
                    (multiple-value-bind (left right) (recur (%treap-right treap))
                      (setf (%treap-right treap) left)
                      (update-count treap)
                      (values treap right)))
                   (t
                    (multiple-value-bind (left right) (recur (%treap-left treap))
                      (setf (%treap-left treap) right)
                      (update-count treap)
                      (values left treap))))))
    (recur treap)))

(declaim (inline treap-insert))
(defun treap-insert (key treap &key (order #'<))
  "Destructively inserts KEY into TREAP and returns the resultant treap."
  (declare ((or null treap) treap)
           (function order))
  (let ((node (%make-treap key (random most-positive-fixnum))))
    (labels ((recur (treap)
               (declare (treap node))
               (cond ((null treap) node)
                     ((> (%treap-priority node) (%treap-priority treap))
                      (setf (values (%treap-left node) (%treap-right node))
                            (treap-split (%treap-key node) treap :order order))
                      (update-count node)
                      node)
                     (t
                      (if (funcall order (%treap-key node) (%treap-key treap))
                          (setf (%treap-left treap)
                                (recur (%treap-left treap)))
                          (setf (%treap-right treap)
                                (recur (%treap-right treap))))
                      (update-count treap)
                      treap))))
      (recur treap))))

(defun treap-map (function treap)
  "Successively applies FUNCTION to TREAP[0], ..., TREAP[SIZE-1]. FUNCTION must
take one argument."
  (declare (function function))
  (when treap
    (treap-map function (%treap-left treap))
    (funcall function (%treap-key treap))
    (treap-map function (%treap-right treap))))

(defmethod print-object ((object treap) stream)
  (print-unreadable-object (object stream :type t)
    (let ((init t))
      (treap-map (lambda (key)
                   (if init
                       (setq init nil)
                       (write-char #\  stream))
                   (write key :stream stream))
                 object))))

(define-condition invalid-treap-index-error (type-error)
  ((treap :initarg :treap :reader invalid-treap-index-error-treap)
   (index :initarg :index :reader invalid-treap-index-error-index))
  (:report
   (lambda (condition stream)
     (format stream "Invalid index ~W for treap ~W."
             (invalid-treap-index-error-index condition)
             (invalid-treap-index-error-treap condition)))))

(declaim (ftype (function * (values fixnum &optional)) read-fixnum))
(defun read-fixnum (&optional (in *standard-input*))
  (declare #.OPT)
  (macrolet ((%read-byte ()
               `(the (unsigned-byte 8)
                     #+swank (char-code (read-char in nil #\Nul))
                     #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil))))
    (let* ((minus nil)
           (result (loop (let ((byte (%read-byte)))
                           (cond ((<= 48 byte 57)
                                  (return (- byte 48)))
                                 ((zerop byte) ; #\Nul
                                  (error "Read EOF or #\Nul."))
                                 ((= byte #.(char-code #\-))
                                  (setf minus t)))))))
      (declare ((integer 0 #.most-positive-fixnum) result))
      (loop
        (let* ((byte (%read-byte)))
          (if (<= 48 byte 57)
              (setq result (+ (- byte 48) (* 10 (the (integer 0 #.(floor most-positive-fixnum 10)) result))))
              (return (if minus (- result) result))))))))

(defmacro dbg (&rest forms)
  #+swank
  (if (= (length forms) 1)
      `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms))
      `(format *error-output* "~A => ~A~%" ',forms `(,,@forms)))
  #-swank (declare (ignore forms)))

(defmacro define-int-types (&rest bits)
  `(progn
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits)
     ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits)))
(define-int-types 2 4 7 8 15 16 31 32 62 63 64)

(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 (princ obj stream) (terpri stream))))

(defconstant +mod+ 998244353)

;; Body
;;;
;;; Arithmetic operations with static modulus
;;;

(defmacro define-mod-operations (&optional (divisor 1000000007))
  `(progn
     (defun mod* (&rest args)
       (reduce (lambda (x y) (mod (* x y) ,divisor)) args))

     (sb-c:define-source-transform mod* (&rest args)
       (if (null args)
           1
           (reduce (lambda (x y) `(mod (* ,x ,y) ,',divisor)) args)))

     (defun mod+ (&rest args)
       (reduce (lambda (x y) (mod (+ x y) ,divisor)) args))

     (sb-c:define-source-transform mod+ (&rest args)
       (if (null args)
           0
           (reduce (lambda (x y) `(mod (+ ,x ,y) ,',divisor)) args)))

     (define-modify-macro incfmod (delta divisor)
       (lambda (x y divisor) (mod (+ x y) divisor)))

     (define-modify-macro decfmod (delta divisor)
       (lambda (x y divisor) (mod (- x y) divisor)))))

(define-mod-operations 998244353)

(defun main ()
  (declare #.OPT
           (inline sort))
  (let* ((n (read))
         (xs (make-array n :element-type 'int32))
         (ys (make-array n :element-type 'int32))
         (powers (make-array 200001 :element-type 'uint32))
         (ord-xs (make-array n :element-type 'uint32))
         (res 0))
    (declare (uint32 n res)
             ((simple-array uint32 (*)) ord-xs))
    ;; construct table of 2^n
    (setf (aref powers 0) 1)
    (loop for i from 1 below (length powers)
          do (setf (aref powers i)
                   (mod* 2 (aref powers (- i 1)))))
    (dotimes (i n)
      (setf (aref xs i) (read-fixnum)
            (aref ys i) (read-fixnum)))
    (dotimes (i n)
      (setf (aref ord-xs i) i))
    (setf ord-xs (sort ord-xs (lambda (i j) (< (aref xs i) (aref xs j)))))
    ;; L R U D
    (incfmod res (mod* (- n 4) (- (aref powers n) 1)) +mod+)
    ;; LU LD
    (let (treap)
      (loop for i from 0 below n
            do (let* ((ord (aref ord-xs i))
                      (y (aref ys ord))
                      (ld (treap-bisect-left y treap))
                      (lu (- (treap-count treap) ld)))
                 (incfmod res (aref powers ld) +mod+)
                 (incfmod res (aref powers lu) +mod+)
                 (setq treap (treap-insert y treap)))))
    ;; RU RD
    (let (treap)
      (loop for i from (- n 1) downto 0
            do (let* ((ord (aref ord-xs i))
                      (y (aref ys ord))
                      (rd (treap-bisect-left y treap))
                      (ru (- (treap-count treap) rd)))
                 (incfmod res (aref powers rd) +mod+)
                 (incfmod res (aref powers ru) +mod+)
                 (setq treap (treap-insert y treap)))))
    (println res)))

#-swank (main)