void heapSort(int n){
int i;
//build heap
for(i = (n - 1)/2; i >= 0; i--){
percDown(i, n);
}
//delete max
for(i = n - 1; i > 0; i--){
swap(a[0], a[i]);
percDown(0, i);
}
}
void Heap::add(Triplet &t) {
size_++;
array.push_back(t);
percDown(size_);
}
