maximum length subarray such that maximum difference is less than k

Given a array and a number k , find a subarray of maximum length such that the difference between each element in the subarray is less than k.
e.g [2,1,8,12,10,15,12,25] and k=7
Ans - [8,12,10,15,12]

Code:
#include <stdio.h>
#include <stdlib.h>

typedef struct
{
    int start;
    int end;
}Ret;


Ret maxsubarr(int a[], int n, int k)
{
    Ret r = {0, 0};


    int start = 0, end = 0;
    int max = 0, min = 0;

    int i;

    int d1, d2;

    int numcomp = 0; //number of comparisons to find the complexity

    for(i = 1; i < n; ++i) //loop through all the elements
    {
        d1 = a[max] - a[i];
        d2 = a[min] - a[i];

        numcomp += 2;

        if(abs(d1) <= k &&  abs(d2) <= k)//a[max] - k <= a[i] <= a[min] + k
        {
            end = i;
            if(a[max] < a[i])
            {
                max = i;
            }
            else if(a[min] > a[i])
            {
                min = i;
            }

            numcomp += 2;
        }

        else
        {
            if((end - start) > (r.end - r.start)) //end of turn
            {
                r.start = start;
                r.end = end;
            }

            if(d1 < -k || d2 > k) //a[i] > a[max] + k or a[i] < a[min] - k
            {
                //out of bounds, reset
                max = min = end = start = i;
            }
            else  //a[min] - k <= a[i] <= a[max] + k
            {
                int j, x;
                end = i;

                if(d1 >= -k) //a[i] <= a[max] + k
                {
                    start = min + 1;

                    max = i;

                    //eliminate elements < x and find min
                    x = a[max] - k;

                    for(j = start + 1; j < end; j++)
                    {
                        numcomp++;
                        if(a[j] < x)
                            start = j + 1;
                    }

                    min = start;
                    for(j = start + 1; j < end; j++)
                    {
                        numcomp++;
                        if(a[min] > a[j])
                            min = j;
                    }
                }
                else //a[i] >= a[min] - k
                {
                    start = max + 1;

                    min = i;

                    x = a[min] + k;

                    //eliminate elements > x and find max

                    for(j = start + 1; j < end; j++)
                    {
                        numcomp++;
                        if(a[j] > x)
                            start = j + 1;
                    }

                    max = start;
                    for(j = start + 1; j < end; j++)
                    {
                        numcomp++;
                        if(a[max] < a[j])
                            max = j;
                    }
                }

            }

        }

    }

    if((end - start) > (r.end - r.start))
    {
        r.start = start;
        r.end = end;
    }

    printf("numcomp %d, numele %d\n", numcomp, n);
    return r;

}

int main()
{
    int a[] = {2,1,8,12,10,15,12,25};

    Ret r = maxsubarr(a,sizeof(a)/sizeof(int), 7);

    int i;

    for(i = r.start; i <= r.end; ++i)
        printf("%d ", a[i]);

    printf("\n");
    system("pause");
}