int pivot = rand()%(right-left)+left;

swap(A[pivot], A[left]);

pivot = left;

int i = left, j = right-1;

while(1){

while(A[i]<=A[pivot]) i++;

while(A[j]>A[pivot]) j--;

if(i<j){

swap(A[i], A[j]);

}else{

break;

}

}

swap(A[left], A[j]);

return j;

if(right-left>1){

int pos = partition(A, left, right);

cout<<"pos "<<pos<<endl;

qsort(A, left, pos-1);

qsort(A, pos+1, right);

}

int A[256];

int N = 25;

for(int i=0; i<N; i++){

A[i] = (int) rand()%1000;

}

qsort(A, 0, N);

for(int i=0; i<N; i++){

cout<<A[i]<<endl;

}

return 0;