Ram space exhausted while creating a Binary Search Tree of 60000 elements - c++

Question

I am trying to build a huge binary search tree:
class Node
{
public:
int value;
shared_ptr<Node> left;
Node* right;
Node(int v):value(v){}
void addLeft(){
static int i;
shared_ptr<Node> node=make_shared<Node>(i);
left=node;
cout<<i++<<endl;
if(i<60000)
node->addLeft();
}
};
int main(){
shared_ptr<Node>root=make_shared<Node>(9);
root->addLeft();
return 0;
}
I get a seg fault over running this code, in valgrind I have this report:
==17373== Stack overflow in thread #1: can't grow stack to 0xffe801000
Any clue on how to build the BST without overflowing the RAM space?
Any help is much appreciated

Answer 1

Exceeding the stack is not the same as exceeding your RAM. Function calls accumulate on the stack, the problem is you are trying to place 60000 function calls and variables on the stack. Convert your function to a loop and you will be fine. It will even get rid of that terrible static int i.
Here is a version of your function using a for loop with no recursion.
void addLeft()
{
left = std::make_shared<Node>(0);
// tail is the last element to have been added to the tree
std::shared_ptr<Node> tail = left;
std::cout << 0 << std::endl;
// Add nodes from 1 to 60000 inclusively
for (int i = 1; i <= 60000; ++i)
{
std::cout << i << std::endl;
tail->left = std::make_shared<Node>(i);
tail = tail->left;
}
}