Problem:
Merge Sort

Write a program of a Merge Sort algorithm implemented by the following pseudocode. You should also report the number of comparisons in the Merge function.

Merge(A, left, mid, right)
n1 = mid - left;
n2 = right - mid;
create array L[0...n1], R[0...n2]
for i = 0 to n1-1
do L[i] = A[left + i]
for i = 0 to n2-1
do R[i] = A[mid + i]
L[n1] = SENTINEL
R[n2] = SENTINEL
i = 0;
j = 0;
for k = left to right-1
if L[i] <= R[j]
then A[k] = L[i]
i = i + 1
else A[k] = R[j]
j = j + 1

Merge-Sort(A, left, right){
if left+1 < right
then mid = (left + right)/2;
call Merge-Sort(A, left, mid)
call Merge-Sort(A, mid, right)
call Merge(A, left, mid, right)

Input

In the first line n is given. In the second line, n integers are given.

Output

In the first line, print the sequence S. Two consequtive elements should be separated by a space character.

In the second line, print the number of comparisons.

Constraints

n ≤ 500000

0 ≤ an element in S ≤ 109

Sample Input 1

10
8 5 9 2 6 3 7 1 10 4

Sample Output 1

1 2 3 4 5 6 7 8 9 10
34

Notes

Solution in Go (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

var (
	SENTINEL = 2000000000
	cnt      = 0
)

func main() {
	fmt.Println(answer(os.Stdin))
}

func answer(r io.Reader) string {
	n := 0

	sc := bufio.NewScanner(r)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	n, _ = strconv.Atoi(sc.Text())
	A := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		A[i], _ = strconv.Atoi(sc.Text())
	}

	mergeSort(A, n, 0, n)

	result := strings.TrimRight(fmt.Sprintf("%+v", A)[1:], "]") + "\n"
	return result + strconv.Itoa(cnt)
}

func merge(A []int, n, left, mid, right int) {
	n1 := mid - left
	n2 := right - mid
	L, R := make([]int, n1+1), make([]int, n2+1)
	for i := 0; i < n1; i++ {
		L[i] = A[left+i]
	}
	for i := 0; i < n2; i++ {
		R[i] = A[mid+i]
	}
	L[n1], R[n2] = SENTINEL, SENTINEL

	i, j := 0, 0
	for k := left; k < right; k++ {
		cnt++
		if L[i] <= R[j] {
			A[k] = L[i]
			i++
			continue
		}
		A[k] = R[j]
		j++
	}
}

func mergeSort(A []int, n, left, right int) {
	if left+1 < right {
		mid := (left + right) / 2
		mergeSort(A, n, left, mid)
		mergeSort(A, n, mid, right)
		merge(A, n, left, mid, right)
	}
}