[C++]Algoritmul lui Dijkstra

#include<iostream.h>
#include<fstream.h>

const int maxi = 500;
int i, j, a[100][100], arc, c, r, q, poz, x, y, s[100], t[100], d[100], mini, n;
    ifstream f("date.in");
void citire()
{

    f>>n;
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=n; j++)
            a[i][j] = maxi;
        a[i][i] = 0;
    }
    f>>arc;
    for(int i=1; i<=arc; i++)
    {
        f>>x>>y>>c;
        a[x][y] = c;
    }

}

void drum(int i)
{
    if(t[i])
        drum(t[i]);
    cout<<i<<" ";
}

int main()
{
    citire();
    cout<<"Punct de plecare: "; cin>>r;
    cout<<"Punct de sosire: "; cin>>q;
    cout<<'\n';
    s[r] = 1;
    for(int i=1; i<=n; i++)
    {
        d[i] = a[r][i];
        if(i != r) if(d[i] < maxi) t[i] = r;
    }
    for(int i=1; i<=n-1; i++)
    {
        mini=maxi;
        for(int j=1; j<=n; j++)
            if(s[j] == 0)
                if(d[j] < mini)
                {
                    mini = d[j];
                    poz = j;
                }
        s[poz] = 1;
        for(int j=1; j<=n; j++)
            if(s[j] == 0)
                if(d[j] > d[poz] + a[poz][j])
                {
                    d[j] = d[poz] + a[poz][j];
                    t[j] = poz;
                }
    }
    if(r < q)
    {
        for(int i=r; i<=q; i++)
            if(i != r)
                if(t[i])
                    if(i == q)
                    {
                        cout<<"Drumul de la "<<r<<" la "<<i<<" este "<<d[i]<<" si trece prin varf:";
                        drum(i);
                        cout<<'\n';
                    }
                    else cout<<"Nu avem drum de la "<<r<<" la "<<i<<'\n';
    }
    else
    {
        for(int i=r; i>=q; i--)
            if(i != r)
                if(t[i])
                    if(i == q)
                    {
                        cout<<"Drumul de la "<<r<<" la "<<i<<" este "<<d[i]<<" si trece prin varf.";
                        drum(i);
                        cout<<'\n';
                    }
                    else cout<<"Nu avem drum de la "<<r<<" la "<<i<<'\n';
    }
    f.close();
    return 0;
}