Merge Sort

#include <stdio.h>

void merge_sort(int [], int, int);

void merge_array(int [], int, int, int);

main()

{

int a[50], n, i;

printf("\nEnter size of an array: ");

scanf("%d", &n);

 printf("\nEnter elements of an array:\n");

for(i=0; i<n; i++)

scanf("%d", &a[i]);

 merge_sort(a, 0, n-1);

 printf("\n\nAfter sorting:\n");

for(i=0; i<n; i++)

printf("\n%d", a[i]);

getch();

}

void merge_sort(int a[], int beg, int end)

{

int mid;

if (beg < end)

{

mid = (beg+end)/2;

merge_sort(a, beg, mid);

merge_sort(a, mid+1, end);

merge_array(a, beg, mid, end);

}

}

void merge_array(int a[], int beg, int mid, int end)

{

int i, left_end, num, temp, j, k, b[50];

for(i=beg; i<=end; i++)

b[i] = a[i];

i = beg;

j = mid+1;

k = beg;

while ((i<=mid) && (j<=end))

{

if (b[i] <= b[j])

{

a[k] = b[i];

i++; k++;

}

else

{

a[k] = b[j];

j++; k++;

}

}

if (i <= mid)

{

while (i <= mid)

{

a[k] = b[i];

i++; k++;

}

}

else

{

while (j <= end)

{

a[k] = b[j];

j++; k++;

}

}

}