Program:
#include <iostream>
using namespace std;
#include <conio.h>
int comp=0;
void merge(int *,int, int , int );
void mergesort(int *a, int low, int high)
{
int mid;
if (low < high)
{
mid=(low+high)/2;
mergesort(a,low,mid);
mergesort(a,mid+1,high);
merge(a,low,high,mid);
}
return;
}
void merge(int *a, int low, int high, int mid)
{
int i, j, k, c[50];
i = low;
k = low;
j = mid + 1;
while (i <= mid && j <= high)
{
if(a[i] < a[j])
{
c[k] = a[i];
k++;
i++;
comp++;
}
else
{
c[k] = a[j];
k++;
j++;
comp++;
}
}
while (i <= mid)
{
c[k] = a[i];
k++;
i++;
}
while (j <= high)
{
c[k] = a[j];
k++;
j++;
}
for (i = low; i < k; i++)
{
a[i] = c[i];
}
}
int main()
{
int a[20], i, b[20];
cout<<"enter the elements\n";
for (i = 0; i < 5; i++)
{
cin>>a[i];
}
mergesort(a, 0, 4);
cout<<"sorted array\n";
for (i = 0; i < 5; i++)
{
cout<<a[i]<<"\n";
}
cout<<"the no. of comparisons:\n"<<comp<<endl;
getch();
}
Output:
