void Merge(int a[], int d1, int c1, int c2, int b[])

{

int i,j,k;

i=k=d1;

j=c1+1;

while ((i<=c1) && (j<=c2))

if (a[i]<a[j])

b[k++]=a[i++];

else

b[k++]=a[j++];

while (i<=c1)

b[k++]=a[i++];

while (j<=c2)

b[k++]=a[j++];

}

void mpass(int a[], int b[], int n, int l)

{

int i,j;

i=-1;

while (i+2*l<n)

{

Merge(a,i+1,i+l,i+2*l,b);

i+=2*l;

}

if (i+l<n-1)

Merge (a,i+1,i+l,n-1,b);

else

for (j=i+1;j<n;j++)

b[j]=a[j];

}

void mergesort(int a[], int n)

{

int l, b[100];

l=1;

while (l<n)

{

mpass(a,b,n,l);

l=2*l;

mpass(b,a,n,l);

l=2*l;

}

}