Again, that's stupidly easy. Right is bigger, left is smaller. If the current node is a leaf, insert left if smaller and right if bigger. If not a leaf nods,

Again, that's stupidly easy. Right is bigger, left is smaller. If the current node is a leaf, insert left if smaller and right if bigger. If not a leaf nods, run the method recursively on the left it it's smaller, on the right if it's bigger. If they asked you to write a self-balancing binary tree it's one thing, but there's nothing tricky about writing a normal ordered binary tree.