Program in C to demonstrate Merge Sort

Write a program in C to demonstrate Merge Sort

#define MAXARRAY 10

void mergesort(int a[], int low, int high);

int main(void) {

            int array[MAXARRAY];

            int i = 0;

            /* load some random values into the array */

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

                        array[i] = rand() % 100;

            /* array before mergesort */

            printf("Before :");

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

                        printf(" %d", array[i]);

            printf("\n");

            mergesort(array, 0, MAXARRAY - 1);

            /* array after mergesort */

            printf("Mergesort :");

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

                        printf(" %d", array[i]);

            printf("\n");

            return 0;

}

void mergesort(int a[], int low, int high) {

            int i = 0;

            int length = high - low + 1;

            int pivot = 0;

            int merge1 = 0;

            int merge2 = 0;

            int working[length];

            if(low == high)

                        return;

            pivot = (low + high) / 2;

            mergesort(a, low, pivot);

            mergesort(a, pivot + 1, high);

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

                        working[i] = a[low + i];

            merge1 = 0;

            merge2 = pivot - low + 1;

           

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

            {

                        if(merge2 <= high - low)

                                    if(merge1 <= pivot - low)

                                                if(working[merge1] > working[merge2])

                                                            a[i + low] = working[merge2++];

                                                else

                                                            a[i + low] = working[merge1++];

                                    else

                                                a[i + low] = working[merge2++];

                        else

                                    a[i + low] = working[merge1++];

            }

}