Is balanced segmentation fault

#include<bits/stdc++.h>
using namespace std;

class node{
public:
int data;
node* left;
node* right;

node(int d){
data=d;
left=NULL;
right=NULL;
}
};
void create(node* &root){
int d;
cin>>d;
root=new node(d);

string left,right;
cin>>left;
if(left=="true"){

 //cin>>d;
 //root->left=new node(d);
 create(root->left);
}
 cin>>right;
if(right=="true"){
	//cin>>d;
	//root->right=new node(d);
  create(root->right);
}

}

class HBpair{

public:
int height;
bool balance;
};

HBpair heightbst(node* root){
HBpair p;
if(root==NULL){
p.height=0;
p.balance =true;

}
HBpair left=heightbst(root->left);
HBpair right=heightbst(root->right);
p.height=max(left.height,right.height)+1;
if(abs(left.height -right.height)<=1 && left.balance && right.balance){
    p.balance=true;
}
else{
    p.balance=false;
}
return p;

}

int main(){
node* root=NULL;
create(root);
if(heightbst(root).balance){
cout<<“true”;

}
else{
    cout<<"false";
}
return 0;

}

why it shows segmentation fault

@kumarakash121005,
I can see you solved it and got 100 points, still having doubts?

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