What is my mistake ?

i have coursework and i wrote the program but its not working ! can you help me about this

Assignment

Write a program for

-Creating a graph with n verticles and m edges.
-Counting the all isolated verticles in the graph

The Values of n and m are set by user.

The result should be shown appropriately on the screen of the computer.


And My Codes

Code:

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// silinecek void edge_add code error
#include <iostream.h>
#include <stdlib.h>

const int v_n=10;
int i;
struct dgraph{
        char vertex;
    dgraph *gec;
}*gr[v_n];


int vertex_check(dgraph *gr[v_n], char ver){
        i=0;
        while(gr[i]){
                if(gr[i]->vertex==ver)
                        return 1;
                i++;
        }
        return 0;
}

void vertex_add(dgraph *gr[v_n], char ver){
        if(vertex_check(gr,ver)==0){
                int y=0;
                while(gr[y] && (y<v_n))
                        y++;
                gr[y]=new dgraph;
                gr[y]->vertex=ver;
                gr[y]->gec=NULL;
                cout << "\nVertex " << ver << " added.\n";
        }
        else
                cout << "\nError.";
}

bool edge_check(dgraph *gr[v_n], char ch1, char ch2){
        if((vertex_check(gr, ch1) && vertex_check(gr, ch2))==1){
                int say=0;
                while(gr[say]->vertex!=ch1)
                        say++;
                dgraph *point=gr[say];
                while(point->vertex!=ch2 && point->gec!=NULL){
                        point=point->gec;
                        if(point->vertex==ch2)
                                return true;
                }
        }
        return false;
}

void edge_add(dgraph *gr[v_n], char ch1, char ch2){
        if(edge_check(gr,ch1,ch2)==true)
                cout << "\nEdge exists.";
        else{
                if(vertex_check(gr,ch1)==0)
                        vertex_add(gr,ch1);
                if(vertex_check(gr,ch2)==0)
                        vertex_add(gr,ch2);
                dgraph *p;
                int gez=0;
                while(gr[gez]->vertex!=ch1)
                        gez++;
                p=new dgraph;
                p->vertex=ch2;
                p->gec=gr[gez]->gec;
                gr[gez]->gec=p;
                cout << "\n\nEdge added: " << ch1 << "->" << ch2 << "\n";
                }
}

void yunus(){
        int a=0;
        while(gr[a]!=NULL){
                cout << "\n1\n";
                a++;
        }
}


void main(){
        int choice,vertices,edges,fa;
        int sayac=0;
        char vertex_name,edge_name1,edge_name2;
        cout << "Number of vertices:";
        cin >> vertices;
        cout << "\nNumber of edges:";
        cin >> edges;
        do{
                do{
                cout << "      \n\n[MENU]\n";
                cout << "1-> Add vertex\n";
                cout << "2-> Add edge between Vertex 1 & Vertex 2\n";
                //cout << "3-> List vertices with 3 out-degrees\n";
                cout << "4-> Exit\n";
                cout << "    Choice:";
                cin >> choice;
        }
        while(choice<1 && choice>4);
        switch(choice){
        case 1:
                for(fa=0;fa<vertices;fa++){
                        cout << "\nVertex:";
                    cin >> vertex_name;
                    vertex_add(gr,vertex_name);
                }
                        break;
        case 2:
                for(fa=0;fa<edges;fa++){
                        cout << "\nVertex 1:";
                        cin >> edge_name1;
                        cout << "Vertex 2:";
                        cin >> edge_name2;
                        while(gr[sayac]->vertex!=edge_name1)
                                sayac++;
                        edge_add(&gr[sayac],edge_name1,edge_name2);
                        sayac=0;
                }
                        break;

        /*case 3:
                yunus();
                break;*/
        case 4:
                exit(1);
        }
        }
        while(choice!=4);
}

---

It would be good if you describe "it's not working" in some better terms, e.g. "When I use choice X, with the following data ... I expect to get ... but I get ...." or "When I do the following steps .... it crashes with ...."

The .... bits are obviously also necessary to fill in with whatever is the relevant facts.

--
Mats

its working but after the compiling when i start to add edges adn vertices i have an error :(

If you can't explain to yourself what the problem is, you can't program it. If you can't explain to us what the problem is, you can't expect help. The phrase "have an error" could mean 100 things. Does it crash? Does it give the wrong output?

hi,
here the problem is exactly about the function "edge_add". because:
run the programme. then input 4 vertices : a,b,c,d. after that, begin inputting the edges:
a->b... ok.
b->a when you input this egde, you will see "vertex added." on the screen. now, we have 5 vertices in the array: a,b,c,d,a
that is the problem.

Quote:

---

Originally Posted by anathex

hi,
here the problem is exactly about the function "edge_add". because:
run the programme. then input 4 vertices : a,b,c,d. after that, begin inputting the edges:
a->b... ok.
b->a when you input this egde, you will see "vertex added." on the screen. now, we have 5 vertices in the array: a,b,c,d,a
that is the problem.

---

Exactly thats a problem ! im sorry that my english is not very good! i cant translate that :(

???? anyone can help ????

Dude, what the heck? You waited 7 minutes and posted again. Don't spam. If you spent as much time working on your program as you're probably doing checking this topic, you might have solved it.

I might check this out later.

> void main()
main returns an int, see the FAQ

> cout << "Number of vertices:";
> cin >> vertices;
> cout << "\nNumber of edges:";
> cin >> edges;
What were your responses to these questions?
Anything >= 10 and your code is in trouble.

> #include <iostream.h>
> #include <stdlib.h>
Does your compiler understand this?

Code:

---

#include <iostream>
#include <cstdlib>
using namespace std;

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If not, your compiler is old.

Thanks Salem I will try again with like that

Erm, my suggested change won't actually fix any bugs in your program. It just tells us whether you're using a fossil, or something more modern with out-of-date programming technique.