quicksort program provides partially sorted output

Question

Below simple quick sort code with last element as pivot,almost works but except the last element fails to get sorted. Any thoughts where this program went wrong?

Here's the output:

$a.out
 4 3 5 2 1 3 2 3 //input
 1 2 2 3 3 3 5 4 //output

Simple swap looks fine

void swap ( int* a, int* b )
{
    int t = *a;
    *a = *b;
    *b = t;
}

Hmm..fine too ..may issue with end?

int partition(int a[],int start,int end){
int pivot = a[end];
int pindex=start;int i;

    for ( i=start; i <= end-1; i++){
       if (a[i] <= pivot){
           swap(&a[i],&a[pindex]);pindex++;
       }
    }
    swap(&a[pindex],&a[pivot]);
    return (pindex + 1);
}

Surely looks good.

void quicksort(int a[],int start,int end){
int pindex;

    if (start < end){
        pindex = partition(a,start,end-1);
        quicksort(a,start,pindex-1);
        quicksort(a,pindex+1,end);
    }
}

Simple main call

int main(){
    int a[8] = {4, 3, 5, 2, 1, 3, 2, 3};
    int i=0;

    for(i=0;i<8;i++)
        printf(" %d", a[i]);
    quicksort(a,0,8);
    printf("\n");
    for(i=0;i<8;i++)
        printf(" %d", a[i]);
}

Answer 1

Okay couple of changes

As doptimusprime pointed return pindex

int partition(int a[],int start,int end){
    int pivot = a[end];
    int pindex=start;int i;
    for ( i=start; i <= end-1; i++){
        if (a[i] <= pivot){
            swap(&a[i],&a[pindex]);pindex++;
        }
    }
    swap(&a[pindex],&a[end]);
    return (pindex);
}

Adjust your quicksort function accordingly

void quicksort(int a[],int start,int end){
    int pindex;

    if (start < end){
        pindex = partition(a,start,end-1);
        quicksort(a,start,pindex); // no pindex-1
        quicksort(a,pindex+1,end);
    }
}