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 <stdio.h>
#define MAX 500000
#define Large 2000000000
int cnt;
int L[250000+2];
int R[250000+2];
int A[MAX];

void merge1(int l,int m,int r){
  int n1,n2,i;
  n1=m-l;   
  n2=r-m;    
  for(i=0;i<n1;i++){
    L[i]=A[l+i];
  }
  for(i=0;i<n2;i++){
    R[i]=A[m+i];
  }
  L[n1]=Large;
  R[n2]=Large;
  int i1=0,i2=0,j;
  for(j=l;j<r;j++){
    if(L[i1]<=R[i2]){
      A[j]=L[i1];
      i1++;
    }else{
      A[j]=R[i2];
      i2++;
    }
    cnt++;
  }
}
 
void mergesort(int l, int r){
  int m;
  if(l+1<r){
      m=(r+l)/2;
      mergesort(l,m);
      mergesort(m,r);
      merge1(l,m,r);
  }
}
 
 
 
int main() {
  int n,i;
  scanf("%d\n",&n);
  for(i=0;i<n;i++) scanf("%d",&A[i]);
  mergesort(0,n);
  for(i=0;i<n;i++){
    if(i==n-1)printf("%d\n",A[i]);
    else printf("%d ",A[i]);
  }
  printf("%d\n",cnt);
  return 0;
}