Описать граф в виде списка и посчитать его вес.

#include<iostream>
#include<fstream>
#include<cmath>
using namespace std;
struct graph
{
    int x1,x2;
    int y1,y2;
    double weight;
};
struct node
{
    graph G;
    node* next;
};
void push (node* &p, graph G)
{
    node *temp;
    temp = new node;
    temp->G = G;
    temp->next =p;
    p= temp;


}

void show (node* &p)
{
    while (p)
    {
        cout<<p->G.x1 <<" "<< p->G.y1 <<" "<< p->G.x2<<" " << p->G.y2 << " "<<p->G.weight<<endl;
        p = p->next;
    }
}
void read (node* &p,ifstream &file)
{
    p = NULL;
    graph G;
    while (file >> G.x1 >>G.y1 >> G.y2 >>G.x2)
    {

        G.weight = sqrt((pow(G.x1 - G.x2, 2)+pow(G.y1 - G.y2,2)));
        push(p, G);

    }
}
void write (node* &p,ofstream &out)
{
    while (p)
    {
        out<<p->G.x1 <<" "<< p->G.y1 <<" "<< p->G.x2<<" " << p->G.y2 << " "<<p->G.weight<<endl;
               p = p->next;
    }
}
int main()
{
    node *list;
    ifstream f ("input.txt");
    ofstream out ("output.txt");
    read(list, f);
    write(list, out);


}