Lee_cu_liste

#include <fstream>

using namespace std;

ifstream f("matrice.in");
ofstream g ("matrice.out");

struct nod
{
    int x, y;
    nod *urm;
};

int l[100][100],n,m;
int dl[]={-1,0,1,0}, dc[]={0,1,0,-1};
nod *ps, *pb;
nod *p=NULL, *u=NULL;
void citire()
{
    f>>n>>m;
    ps=new nod;
    pb=new nod;
    f>>ps->x>>ps->y;
    f>>pb->x>>pb->y;
    ps->urm=NULL;
    pb->urm=NULL;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            f>>l[i][j];
}

void adaugare(nod *d)
{
    if(p==NULL)
        p=u=d;
    else
    {
        u->urm=d;
        u=d;
    }
}

void bordare()
{
    for(int i=0;i<=n+1;i++)
        l[i][0]=l[i][m+1]=-1;
    for(int j=0;j<=m+1;j++)
        l[0][j]=l[n+1][j]=-1;
}

void Lee()
{
    nod *aux;
    adaugare(ps);
    l[ps->x][ps->y]=1;
    while(p!=NULL && l[pb->x][pb->y]==0)
    {
        for(int i=0;i<4;i++)
        {
            aux=new nod;
            aux->x=p->x+dl[i];
            aux->y=p->y+dc[i];
            aux->urm=NULL;
            if(l[aux->x][aux->y]==0)
            {
                nod *z;
                z=p;
                p=p->urm;
                delete z;
                l[aux->x][aux->y]=l[u->x][u->y]+1;
                adaugare(aux);
            }
        }
    }
}

int main()
{
    bordare();
    if(l[pb->x][pb->y]==0)
        g<<"Nu exista drum.";
    else
        g<<l[pb->x][pb->y];

    return 0;
}