Cod sursa(job #773815)

Utilizator veleanduAlex Velea veleandu Data 2 august 2012 17:37:37
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.83 kb
// rezolvare off-line

#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

# define verf ++poz == hg ? cin.read (ch, hg), poz = 0 : 0
const int hg = 1 << 13;

#define maxn 250005
#define maxm 300005


char ch[hg];
long poz;

    inline void cit ( long &x ) {
        if (ch[0] == '\0') cin.read (ch, hg) ;
        else for (; ch[poz] < '0' || ch[poz] > '9' ; verf) ;
        for (x = 0 ; ch[poz] >= '0' && ch[poz] <= '9' ; x = x * 10 + ch[poz] - '0', verf) ;
    }


    typedef struct { long a,b,rez; } query;
    query Q[maxm];
    long i,n,m,x;
    long Nr[maxn],nr,act;
    long C[maxn];
    vector <long> V[maxn];
    vector <long> QM[maxn];


    void DFs ( long varf )
    {

        nr=1;
        while ( nr>0 )
        {
            varf = Nr[nr];


            if ( !C[varf] )
            {
                long i;
                for ( i=0; i<QM[varf].size(); i++ )
                {
                    if ( Q[ QM[varf][i] ].b > nr )
                        Q[ QM[varf][i] ].rez=0;
                    else
                        Q[ QM[varf][i] ].rez = Nr[nr- Q[ QM[varf][i] ].b ];
                }
            }
            if ( C[varf] == (V[varf].size() ))
                nr--;
            else{
                nr++;
                Nr[nr]=V[varf][C[varf]];
                C[varf]++;
            }
        }
    }



int main()
{
    freopen ("stramosi.in","r",stdin);
    freopen ("stramosi.out","w",stdout);
    cit(n);
    cit(m);
    for ( i=1; i<=n; i++ )
    {
        cit(x);
        V[x].push_back(i);
    }
    for ( i=1; i<=m; i++ )
    {
        cit ( Q[i].a);
        cit ( Q[i].b);

        QM[ Q[i].a ].push_back( i );
    }
    DFs(0);

    for ( i=1; i<=m; i++ )
        printf ("%d\n",Q[i].rez);
}