Question

Hello
I have following struct

struct node {
   std::string word
   std::vector<struct node *> child;
}

When I create the new node, I have no way to initialize child vector.
What I essentially want is to check any element using operator[] is there is valid value.
I want to do following

if ( nodeptr->child[5] )  {
}

But Code crashes at if loop.

Is there other way to handle this.

Answer 1

In this case you would have to provide a constructor for you struct.

struct node {
   node() : word(), child(10, NULL) {}
   std::string word
   std::vector<struct node *> child;
}

This will initialize the vector with 10 NULL-pointers. You can then check if an index is NULL (meaning it does not contain data), or not (it does contain data).