binary tree in order traversal

#include <iostream>
#include<stdlib.h>

using namespace std;

struct node
{
    int data;
    struct node* left;
    struct node* right;
    
};

struct node* crenode(int data)
{
    struct node *a;
    a=(struct node*)malloc(sizeof(struct node));
    a->data=data;
    a->left=NULL;
    a->right=NULL;
}


void inorder(struct node *p)
{
    if(p!=NULL)
    {
        inorder(p->left);
        
        cout<<" "<<p->data;
        
        inorder(p->right);
    }
}

int main()
{
    struct node *q=crenode(12);
    struct node *q1=crenode(42);
    struct node *q2=crenode(95);
    struct node *q3=crenode(65);
    struct node *q4=crenode(32);
    
    q->left=q1;
    q->right=q2;
    q1->left=q3;
    q2->right=q4;
    
    inorder(q);

    return 0;
}