int is_bst_helper(tree *root, int lower, int upper) {
if (root == NULL) {
return 1;
} else
if (root->value < lower || root->value > upper) {
return 0;
}
return is_bst_helper(root->left, lower, root->value) &&
is_bst_helper(root->right, root->value, upper);
}
int is_bst_helper(tree_t* t,tree_node_t* v,void* l,void* r){
if(v==NULL){
return 1;
}
int a,b;
if(l==NULL || t->comparator(v->data,l)>0{
a =1;
}
if(r==NULL || t->comparator(v->data,r)<0){
b = 1;
}
return (a && b && is_bst_helper(t,v->left,l,v->data) && is_bst_helper(t,v->right,v->data,r));
}
int is_bst(tree_t* t){
return is_bst_helper(t,t->root,NULL,NULL);
}
int is_bst(tree *root) {
return is_bst_helper(root, INT_MIN, INT_MAX);
}
