Searching for an object inside a binary search tree - c++

Question

**The trace function is the one I am using to search through the binary search tree it returns the right order of numbers when I search for something within the tree but when I want to see if a number doesn't exist i get segmentation fault **
// Binary search tree
#include <stdio.h>
#include <iostream>
#include <assert.h>
using namespace std;
struct node
{
int data;
node * left;
node * right;
};
node * newNode(int data){
node * newnode = new node();
newnode -> data = data;
newnode -> left = NULL;
newnode -> right = NULL;
return newnode;
}
node* Insert (node * root, int data){
if(root == NULL){
root = newNode(data);
}
else if(data <= root-> data){
root->left = Insert(root->left, data);
}
else{
root -> right = Insert(root->right, data);
}
return root;
};
int Trace(node* root,int find){
node * searcher = root;
if(searcher->data == find){
cout << searcher->data << endl;
}
else if(find <= root -> data){
Trace(searcher->left, find);
cout << searcher ->data<< endl;
}
else if(find >= root -> data){
Trace(searcher->right, find);
cout << searcher ->data << endl;
}
else cout << "not found" << endl;
return searcher-> data;
};
int main(){
node * root = NULL; // creating an empty tree
root = Insert(root, 234234);
root = Insert(root, 2334);
root = Insert(root, 23784);
root = Insert(root, 223);
root = Insert(root, 4244);
root = Insert(root, 673234);
root = Insert(root, 2);
root = Insert(root, 2344);
root = Insert(root, 234);
Trace(root,4244);
return 0;
}

Answer 1

When you are walking through the tree looking for a member that doesn't exist, you'll eventually reach a NULL node. When you try to assess its data, you get a segmentation fault. You can avoid this by checking if the node you are going to assess is valid. For example, change your function Trace to:
int Trace(node* root, int find) {
node * searcher = root;
if(!searcher) {
cout << "Node not found" << endl;
//return something here
}
//rest of function stays the same
}