why my process is returned with Process returned -1073741819 (0xC0000005). Can you please help me with it?

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

struct Node
{
int board[9];
//int father[9];
int g;//depth
int h;
int f;
int index;
struct Node * next;
};
int g=0;
//2->3
int flag=0;
struct Node * open=NULL;
struct Node * curr_open=open;
struct Node * close=NULL;
struct Node * last_close=close;
void close_addition(struct Node * addtoclose,int goal[]){
    cout<<"Inside close addition "<<endl;
    int c=0;
last_close=last_close->next;
last_close=addtoclose;
g++;
for(int i=0;i<9;i++){
    if(last_close->board[i]==goal[i]){
        c++;
    }
    if(c==9){
        flag=1;
    }
    if(flag==1){
        cout<<"g value"<<g<<endl;
    }
}

}

void deletefromopen(priority_queue <int, vector<int>, greater<int> > minf,struct Node*open){
    cout<<"Inside Delete from open"<<endl;
struct Node * temp=((struct Node*)(malloc(sizeof(struct Node))));
struct Node * addtoclose=((struct Node*)(malloc(sizeof(struct Node))));
struct Node * temp_prev=((struct Node*)(malloc(sizeof(struct Node))));
int goal[9]={1,2,3,8,0,4,7,6,5};
if(open->f==minf.top()){
    temp=open;
    open=open->next;
    addtoclose=temp;
    close_addition(addtoclose,goal);//close**************
    free(temp);
}
else{
    while(temp->f!=minf.top()){
        temp_prev=temp;
        temp=temp->next;
    }
    temp_prev->next=temp->next;
    addtoclose=temp;
    close_addition(addtoclose,goal);
    free(temp);
}
}

 //insert

void inserttoopen(int f, int g,int h,int demo[]){
cout<<"Inside INSERT TO OPEN "<<endl;
    struct Node* new_open=((struct Node*)(malloc(sizeof(struct Node))));
for(int i=0;i<9;i++){
    new_open->board[i]=demo[i];
}
new_open->f=f;
new_open->g=g;
new_open->h=h;
curr_open=curr_open->next;
curr_open=new_open;
priority_queue <int, vector<int>, greater<int> > minf;
minf.push(curr_open->f);
deletefromopen(minf,open);

}
int h1vals(struct Node * last_close,int h,int goal[],int x,int y,int g){
    cout<<"Inside h1"<<endl;
    int demo[9]={0};
    for(int i=0;i<9;i++)
    {
        demo[i]=last_close->board[i];
    }
    swap(demo[x],demo[y]);

for(int i=0;i<9;i++)
{   if(goal[i]!=demo[i])
        {
            h++;//h+g
        }
}

int f=h+g;
inserttoopen(f,g,h,demo);

for(int i=0;i<9;i++)
    {
        demo[i]=last_close->board[i];
    }

}

//cout<<"Calculating MISPLACED TILES"<<endl;
//cout<<"MISPLACED Tiles possible board position is: "<<endl;
 //      b++;

        //cout<<demo[i]<<" ";
//if(b==3){
  //  cout<<endl;
    //b=0;
//}
   // }
    //cout<<endl<<"h1 Misplaced value is "<<co<<endl;

int main(){
struct Node * open=NULL;
struct Node * curr_open=open;
struct Node * close=NULL;
struct Node * last_close=close;
    int goal[9]={1,2,3,8,0,4,7,6,5};int zero_pos=0;
    cout<<"Enter the input state"<<endl;
    for(int i=0;i<9;i++)
{
    cin>>close->board[i];
}

cout<<"flag"<<flag<<endl;
while(flag!=1)
{
for(int i=0;i<9;i++)
{
    if(last_close->board[i]==0)
    {
        zero_pos=i;
    }
}
if(zero_pos==0){
    h1vals(last_close,0,goal,0,1,g);
    h1vals(last_close,0,goal,0,3,g);
}
if(zero_pos==1)
{
    h1vals(last_close,0,goal,1,0,g);
    h1vals(last_close,0,goal,1,2,g);
    h1vals(last_close,0,goal,1,4,g);
}
if(zero_pos==2)
{
    h1vals(last_close,0,goal,2,1,g);
    h1vals(last_close,0,goal,2,5,g);
}
if(zero_pos==3)
{
    h1vals(last_close,0,goal,3,0,g);
    h1vals(last_close,0,goal,3,4,g);
    h1vals(last_close,0,goal,3,6,g);
}
if(zero_pos==4)
{
    h1vals(last_close ,0,goal,4,5,g);
    h1vals(last_close, 0,goal,4,3,g);
    h1vals(last_close,0,goal,4,1,g);
    h1vals(last_close,0,goal,4,7,g);
}
if(zero_pos==5)
{
    h1vals(last_close,0,goal,5,4,g);
    h1vals(last_close,0,goal,5,2,g);
    h1vals(last_close,0,goal,5,8,g);
}
if(zero_pos==6)
{
    h1vals(last_close,0,goal,6,7,g);
    h1vals(last_close,0,goal,6,3,g);
}
if(zero_pos==7)
{
    h1vals(last_close,0,goal,7,6,g);
    h1vals(last_close,0,goal,7,8,g);
    h1vals(last_close,0,goal,7,4,g);
}
if(zero_pos==8)
{
    h1vals(last_close,0,goal,8,7,g);
    h1vals(last_close,0,goal,8,5,g);
}


}
return 0;
}

It's not even printing the flag value in the main. This is the output: .

I think it should be because of the declaration of variables in the global and not getting referenced in the main. Please help me sort out the same.