C Program to Implement Bitonic sort

#include <stdio.h>
#include <stdlib.h>
#define MAX 8
#define SWAP(x,y) t = x; x = y; y = t;
 
void compare();
void bitonicmerge(int, int, int);
void recbitonic(int, int, int);
void sort();
 
int data[MAX];
int up = 1;
int down = 0;
 
int main()
{
    int i;
 
    printf("\nEnter the data");
    for (i = 0;i < MAX ;i++)
    {
        scanf("%d", &data[i]);
    }
    sort();
    for (i = 0;i < MAX;i++)
    {
        printf("%d ", data[i]);
    }
}
/*
 * compare and swap based on dir
 */
void compare(int i, int j, int dir)
{
    int t;
 
    if (dir == (data[i] > data[j]))
    {
        SWAP(data[i], data[j]);
    }
}

void bitonicmerge(int low, int c, int dir)
{
    int k, i;
 
    if (c > 1)
    {
         k = c / 2;
        for (i = low;i < low+k ;i++)
            compare(i, i+k, dir);    
        bitonicmerge(low, k, dir);
        bitonicmerge(low+k, k, dir);    
    }
}

void recbitonic(int low, int c, int dir)
{
    int k;
 
    if (c > 1)
    {
        k = c / 2;
        recbitonic(low, k, up);
        recbitonic(low + k, k, down);
        bitonicmerge(low, c, dir);
    }
}

void sort()
{
    recbitonic(0, MAX, up);
}