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++ (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
#define MAX 500000
#define SENTINEL 2000000000

int L[MAX/2+2], R[MAX/2+2];
int cnt;

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

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

int main() {
  int A[MAX], n;
  cnt = 0;

  cin >> n;
  for (int i = 0; i < n; i++) cin >> A[i];

  mergeSort(A, n, 0, n);

  for (int i = 0; i < n; i++) {
    if (i) cout << " ";
    cout << A[i];
  }
  cout << endl;

  cout << cnt << endl;

  return 0;
}