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"
	"os"
	"strconv"
	"strings"
)

var count = 0

func merge(as []int, bs []int) []int {
	var result []int
	as = append(as, 1000000001)
	bs = append(bs, 1000000001)
	i := 0
	j := 0
	for {
		if i == len(as)-1 && j == len(bs)-1 {
			break
		}
		count++
		if as[i] < bs[j] {
			if as[i] < 1000000001 {
				result = append(result, as[i])
				i++
			}
		} else {
			if bs[j] < 1000000001 {
				result = append(result, bs[j])
				j++
			}
		}
	}
	return result
}

func mergeSort(xs []int) []int {
	if len(xs) == 1 {
		return xs
	}
	m := len(xs) / 2
	var as = make([]int, len(xs[:m]))
	copy(as, xs[:m])
	var bs = make([]int, len(xs[m:]))
	copy(bs, xs[m:])
	return merge(mergeSort(as), mergeSort(bs))
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, err := strconv.Atoi(sc.Text())
	if err != nil {
		panic(err)
	}
	return n
}

func printArray(xs []int) {
	fmt.Println(strings.Trim(fmt.Sprint(xs), "[]"))
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n := nextInt(sc)
	xs := make([]int, n)
	for i := 0; i < n; i++ {
		xs[i] = nextInt(sc)
	}
	result := mergeSort(xs)
	printArray(result)
	fmt.Println(count)
}