Cod sursa(job #2395250)

Utilizator NaritaandreiCNAINarita Andrei NaritaandreiCNAI Data 2 aprilie 2019 12:50:03
Problema Stramosi Scor 50
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.01 kb
#include <iostream>
#include <stdio.h>
#include <algorithm>
using namespace std;
FILE *f,*g;
int rmq[25][250002];
int log2[25002];
int n,m;
void read()
{
    fscanf(f,"%d %d",&n,&m);
    for(int i=1; i<=n; i++)
        fscanf(f,"%d",&rmq[0][i]);
}
void logarithm()
{
    for(int i=2;i<=n;i++)
        log2[i]=log2[i/2]+1;
}
void build()
{
    for(int i=1;i<=log2[n];i++)
        for(int j=1; j<=n; j++)
            rmq[i][j]=rmq[i-1][rmq[i-1][j]];
}
int querry(int nod, int lev)
{
    for(int i=0; (1<<i)<=lev; i++)
    {
        if((1<<i) & lev)
        {
            nod=rmq[i][nod];
            if(!nod)
                return 0;
        }
    }
    return nod;
}
int main()
{   int nod,lev;
    f=fopen("stramosi.in", "r");
    g=fopen("stramosi.out", "w");
    read();
    logarithm();
    build();
    for(int i=1;i<=m;i++)
    {
        fscanf(f,"%d %d",&nod,&lev);
        fprintf(g,"%d\n",querry(nod,lev));
    }
    //write();
    fclose(f);
    fclose(g);
    return 0;
}