0 Puts even in asc,neven in desc order

#include <stdio.h>
#define SIZE 10
//PASTEBIN OR ALREADY THERE?
//FIXED:SWAP PASSES THE WHOLE ARRAY, INSTEAD OF JUST 2 ELEMENTS.
//FIGURE OUT:KAK OPISAT ARGUMENTY SWAP IN DECL, DEF, CALL? AND THE WHOLE OF
//SWAP-BODY - WHAT'S GOING ON! I CAN CODE IT, BUT CAN'T EXPLAIN IT!

//https://otvet.mail.ru/question/211822869

void pop_arr(int,int *);
void pr_arr(int,int *);
void even_neven(int,int *);//puts all even els into first part of array, all non-even into second
void sort(int,int *);//puts all even into ascending, all non-even into descending order
//void swap_2_els(int,int *,int,int);//bad realisation, argument the whole array!
void swap_2_els(int *,int *);

int main()
{
    int i,j,k,a[SIZE]={2,4,6,8,0,5,7,3,9,1};//{8,2,5,9,1,3,7,5,3,4};
    pop_arr(SIZE,a);
    pr_arr(SIZE,a);
    even_neven(SIZE,a);
    pr_arr(SIZE,a);
    sort(SIZE,a);
    pr_arr(SIZE,a);

    return 0;
}
void pop_arr(int s,int *a)
{
    int i;
    for(i=0;i<s;i++)
    {
        a[i]= rand()%10;
    }
}
void pr_arr(int s,int *a)
{
    int i;
    for(i=0;i<s;i++)
    {
        printf("%d\t",a[i]);
    }
}
void even_neven(int s,int *a)
{
    int i,j,temp;
    for(i=0;i<s;i++)
    {
        if(a[i]%2)
        {
            for(j=0;j<s;j++)
            {
                if( !(a[j]%2))//a[i]-even,a[j] -neven
                {
                    swap_2_els(&a[i],&a[j]);//a[i] with a[j]
                    j=s;
                }//end of if
            }//end of for j

        }//end of if

    }
}
void sort(int s, int *a)//sorts first half in ascending, second-descending order
{
    int i,j,start,temp;
    for(i=0;i<s;i++)//finds start-index of first neven number
    {
        if(!(a[i]%2))
            start=i,i=s;
    }

    for(i=0;i<s;i++)
    {
        for(j=i;j<s;j++)
        {
            if( (a[i]>a[j]&&i<start-1&& j<start) ||
                (a[i]<a[j]&&i>=start-1&&j>=start))
                swap_2_els(&a[i],&a[j]);
        }
    }

    /*for(i=0;i<start-1;i++)//first half of array, sort in ascending
    {
        for(j=i;j<start;j++)
        {
            if( a[i]>a[j])//
            {
                swap_2_els(a[i],a[j]);
            }
        }
    }*/
    /*for(i=start;i<s-1;i++)//second half of array, sort in descending
    {
        for(j=i;j<s;j++)
        {
            if( a[i]<a[j] )//second part of array
            {
                swap_2_els(a[i],a[j]);
            }
        }
    }*/
}
void swap_2_els(int *el1,int *el2)//how
{
    int temp = *el1;
    *el1 = *el2;
    *el2 = temp;
}