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 C++14 (judge verdict: Accepted)

#include <iostream>
#include <vector>
#include <algorithm>
#define INF 1000000010

using namespace std;

int n, a[500010], cnt=0;

void merge (int left, int mid, int right)
{
    int n1=mid-left, n2=right-mid, L[n1+1], R[n2+1];
    for (int i=0; i<n1; i++) L[i]=a[left+i];
    for (int i=0; i<n2; i++) R[i]=a[mid+i];
    L[n1]=INF; R[n2]=INF;
    int i=0, j=0;
    for (int k=left; k<right; k++)
    {
        cnt++;
        if (L[i]<=R[j])
        {
            a[k]=L[i];
            i++;
        }
        else
        {
            a[k]=R[j];
            j++;
        }
    }
}

void mergesort (int left, int right)
{
    if (left+1<right)
    {
        int mid=(left+right)/2;
        mergesort(left, mid);
        mergesort(mid, right);
        merge(left, mid, right);
    }
}
int main()
{
    cin>>n;
    for (int i=0; i<n; i++) cin>>a[i];
    mergesort(0, n);
    for (int i=0; i<n; i++)
    {
        if (i!=n-1) cout<<a[i]<<' ';
        else cout<<a[i]<<'\n';
    }
    cout<<cnt<<'\n';
    return 0;
}