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>
#include<math.h>
#define INF 1000000000
void merge(int A[],int left,int mid, int right);
void mergesort(int A[],int left,int right);
void list(int A[]);
//int a[500001];

int cnt=0;
int n;
int main()
{
  int i,j;
  scanf("%d",&n);
 
  int a[n];
  for(i=0;i<n;i++){
    scanf("%d",&a[i]);
  }


  
  mergesort(a,0,n);
  list(a);
  printf("%d\n",cnt);
  return 0;
}
void merge(int A[n],int left,int mid, int right){
  int n1,n2;
  n1=mid-left;
  n2=right-mid;
  int L[n1],R[n2],i,j,k;
  //printf("a\n");
  for(i=0;i<n1;i++){
    L[i]=A[left+i];
  }
  //printf("b\n");
  for(i=0;i<n2;i++){
    R[i]=A[mid+i];
  }
  L[n1]=INF;
  R[n2]=INF;
  i=0;
  j=0;
  //printf("c\n");
  for(k=left;k<=right-1;k++){
    if(L[i]<=R[j]){
      A[k]=L[i];
      i++;
       cnt++;
    }else{
      A[k]=R[j];
      j++;
       cnt++;
    }
  }
}
void mergesort(int A[n],int left,int right){
  //printf("test %d %d\n" ,left,right);
  int mid,i;
  // list(A);
  if(left+1<right){
    //printf("%d %d\n",left,right);
    mid=(left+right)/2;
    mergesort(A,left,mid);
    mergesort(A,mid,right);
    // printf("A\n");
    merge(A,left,mid,right);
  }//else
    //printf("!!\n");
}
void list(int A[n]){
  int i;
  //printf("segu\n");
  for(i=0;i<n;i++){
    printf("%d",A[i]);
    if(i!=n-1)printf(" ");
  }
  printf("\n");
}