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 <stdlib.h>
#define INFTY 1000000001
void mergeSort(int [],int,int);
void merge(int [],int,int,int);
int count = 0;
int A[500002];
int L[250001];
int R[250001];

int main(){
    int n,i;
    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%d",&A[i]);
    }
    mergeSort(A,0,n);
    for(i=0;i<n;i++){
        if(i<n-1) printf("%d ",A[i]);
        else printf("%d\n",A[i]);
    }
    printf("%d\n",count);
    return 0;
}
void merge(int A[],int left,int mid,int right){
    int n1,n2,i,j,k;
    /*int *L;
    int *R;*/
    n1 = mid - left;
    n2 = right - mid;
    /*L = calloc(n1,sizeof(int));
    R = calloc(n2,sizeof(int));*/
    for(i=0;i<n1;i++){
        L[i] = A[left + i];
    }
    for(i=0;i<n2;i++){
        R[i] = A[mid+i];
    }
    L[n1] = INFTY;
    R[n2] = INFTY;
    i = 0;
    j = 0;
    for(k = left;k<right;k++){
        if(L[i] <= R[j]){
            A[k] = L[i];
            i = i + 1;
            count++;
        }
        else{
            A[k] = R[j];
            j = j + 1;
            count++;
        }
    }
    /*free(L);
    free(R);*/
}
void mergeSort(int A[],int left,int right){
    int mid;
    if(left+1 < right){
        mid = (left + right)/2;
        mergeSort(A,left,mid);
        mergeSort(A,mid,right);
        merge(A,left,mid,right);
    }
}