Cod sursa(job #863058)

Utilizator marta_diannaFII Filimon Marta Diana marta_dianna Data 23 ianuarie 2013 11:28:58
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.41 kb
#include<fstream>
#include<vector>
#define NMAX 250010
#define MMAX 300010

using  namespace std;

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

struct intrebare
{
    int nr, o;
};

struct intrebare1
{
    int x, y, r;
} b[MMAX];

vector<int> a[NMAX];
vector<intrebare> query[NMAX];

int n, m, ns=0, st[NMAX], x[NMAX];

void Citeste()
{
    int i, x, y;
    intrebare z;

    f>>n>>m;

    for (i=1; i<=n; ++i)
    {
        f>>x;
        a[x].push_back(i);
    }

    for (i=1; i<=m; ++i)
    {
        f>>b[i].x>>b[i].y;
        z.nr=b[i].y; z.o=i;
        query[b[i].x].push_back(z);
    }
}

void DFS(int nod)
{
    int i, pc, xp;
    intrebare z;

    st[++ns]=nod;

    while (ns)
    {
        if (x[ns]<a[st[ns]].size())
        {
            pc=x[ns]; xp=st[ns];
            st[++ns]=a[xp][pc];
            x[ns]=0; x[ns-1]++;
        }
        else
        {
            for (i=0; i<query[st[ns]].size(); ++i)
            {
                z=query[st[ns]][i];
                if (ns-z.nr>0) b[z.o].r=st[ns-z.nr];
                else b[z.o].r=0;

            }
            st[ns]=0;  x[ns--]=0;
        }
    }
}

void Solve()
{
    int i;

    for (i=0; i<a[0].size(); ++i)
        DFS(a[0][i]);

    for (i=1; i<=m; ++i) g<<b[i].r<<"\n";
}

int main()
{
    Citeste();

    Solve();

    f.close();
    g.close();
    return 0;
}