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#include<stdio.h>
#include<conio.h>

//function prototyping
void mergesort(int *a,int *temp,int l,int u);
void merge(int *a,int *temp,int l,int u);

//main method to perform operations
main()
{
      int n;      
      printf("Enter the value of n-array size");
      scanf("%d",&n);
     
      //declaring arrays
      int a[n];
      int temp[n];

      
      //adding contents to array
      for(int i=0;i<n;i++)
     {
               scanf("%d   ",&a[i]);
               temp[i]=0; //intializing temp
     }
      
      puts("Array before sorting : ");
      for(int i=0;i<n;i++)
      printf("%d   ",a[i]);
      
      //calling function
      mergesort(a,temp,0,n-1);
      
      //Displaying sorted array
      puts("\nArray after sorting");
      for(int i=0;i<n;i++)
      printf("%d   ",a[i]);
      getch();
}

//functon to mergesort elements of array
void mergesort(int *a,int *temp,int l,int u)
{
       int m; 
       if(l<u)
       {
             m=(l+u)/2;
             mergesort(a,temp,l,m);
             mergesort(a,temp,m+1,u);
             merge(a,temp,l,u);
       }
}

//function to merge array elements
void merge(int *a,int *temp,int l,int u)
{
         int m=(l+u)/2;
         int i=l,j=m+1;
         int c;
         for(c=l;i<=m&&j<=u;c++)
         {
                if(a[i]==a[j])
                {
                    temp[c++]=a[i];
                    temp[c]=a[i];
                    i++;
                    j++;
                }
                else
                {
                    if(a[i]<a[j])
                    {
                        temp[c]=a[i];
                        i++;
                    }
                    else
                    {
                        temp[c]=a[j];
                        j++;
                    }
                }
         }
         for(;i<=m;)
         temp[c++]=a[i++];
         for(;j<=u;)
         temp[c++]=a[j++];
         for(i=l;i<=u;i++)
         a[i]=temp[i];
}