There is some problem with my deletion code in a binary tree. Whenever I try to delete a node with branching on both sides it crashes, sometimes it also crashes when I have to delete node with one...

#include<iostream>
#include<conio.h>
#include<stdlib.h>
using namespace std;

struct node
{
   int data;
   node *left;
   node *right;
};
node * par(int z,node *root);
node *binary_tree(node *p, int data)
{
  node *temp;
  if(p==NULL)
  {
    p=new node;
    p->data=data;
    p->left=p->right=NULL;
  }
  else if(data>(p->data))
  {
    p->right=binary_tree(p->right,data);

  }
  else
  {
    p->left=binary_tree(p->left,data);
  }
  }


  int search_tree(node *p,int k)
  {
  	  if(p==NULL) return 0;
  	  else if(k==p->data) return 1;
  	  else if(k>=p->data)  search_tree(p->right,k);
  	  else search_tree(p->left,k);



  }

node * find_min(node *p)
  {

      node *t,*temp;
      while(p!=NULL)
      {
          t=p;
          p=p->left;
      }
      return(t);
  }

void del_node(int k,node *root)
{
    node *z,*temp;
    node *parent=par(k,root);
    if(parent->left->data==k) z=parent->left;
    else z=parent->right;
    if(z->left==NULL && z->right==NULL)
    {
        if(parent->right==z)
        {
            parent->right=NULL;
            free(z);
        }
        else
        {
            parent->left=NULL;
            free(z);
        }
    }
    else if(z->left==NULL || z->right==NULL)
    {
        if(z->right!=NULL)
        {
            if(parent->right==z)
            {
                parent->right=z->right;
                free(z);
            }
            else
            {
                parent->left=z->right;
                free(z);
            }
        }
        else if(z->left!=NULL)
        {
            if(parent->right==z)
            {
               parent->right=z->left;
               free(z);
            }
            else
            {
               parent->left=z->right;
               free(z);
            }
        }
    }
    else
    {
       node *m=find_min(z->right);
       cout<<endl<<"min value right of node to be deleted "<<m->data;
       int j=m->data;
       del_node(j,root);
       z->data=j;

    }
}


node * par(int z,node *root)
{
    node *temp=root;
    while(1)
    {
        if(temp->left==NULL && temp->right!=NULL && temp->right->data!=z) temp=temp->right;
        else if(temp->left==NULL && temp->right!=NULL && temp->right->data==z) {return temp;break;}
        else if(temp->left!=NULL && temp->right==NULL && temp->right->data!=z) temp=temp->left;
        else if(temp->left!=NULL && temp->right==NULL && temp->right->data==z) {return temp;break;}
        else
        {
            if(temp->right->data==z || temp->left->data==z) {return temp;break;}
            else if(z>temp->data) temp=temp->right;
            else if(z<temp->data) temp=temp->left;
        }
    }
    return temp;
}


int main()
{
  cout<<endl<<"enter the number of elements you want to insert ";
  int n,val;
  node *root=NULL;
  cin>>n;
  for(int i=0;i<n;i++)>
  {
    cout<<endl<<"enter the value of data ";
    cin>>val;
    root= binary_tree(root,val);
  }
 // cout<<endl<<((root->right)->right)->data;
  cout<<endl<<"enter a number to search in the tree ";
  int k;
  cin>>k;
  int j=search_tree(root,k);
  if(j==1) cout<<endl<<"the number is present in the tree ";
  else cout<<endl<<"the number is not present in the tree";
  cout<<endl<<" enter the number you want to delete ";
  cin>>k;
  del_node(k,root);
  cout<<endl<<"the node was successfully deleted ";


}