Cod sursa(job #3276824)

Utilizator TraianQTraianQ TraianQ Data 14 februarie 2025 19:41:03
Problema Stramosi Scor 80
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.02 kb
#include <fstream>
#include <vector>
using namespace std;
int stramosi[250001][19],pow2[19],log[250001];
int main()
{
    ifstream fin("stramosi.in");
    ofstream fout("stramosi.out");
    pow2[0]=1;
    for(int i=1;i<=18;i++)
        pow2[i]=pow2[i-1]*2;
    int n,m,a,b;
    fin>>n>>m;
    log[1]=0;
    log[2]=1;
    int L=1;
    for(int i=2;i<=n;i*=2)
    {
        int nextp=i*2-1;
        nextp=min(nextp,n);
        for(int j=i;j<=nextp;j++)
            log[j]=L;
        L++;
    }
    for(int i=1;i<=n;i++)
    {
        fin>>a;
        stramosi[i][0]=a;
    }
    for(int j=1;j<=18;j++)
    {
        for(int i=1;i<=n;i++)
        {
            stramosi[i][j]=
            stramosi[stramosi[i][j-1]][j-1];
        }
    }
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b;
        int nod=a;
        for(int j=18;b>0;)
            {
                j=log[b];
                nod=stramosi[nod][j];
                b-=pow2[j];
            }
        fout<<nod<<'\n';
    }
    return 0;
}