Cod sursa(job #1630679)

Utilizator DenisONIcBanu Denis Andrei DenisONIc Data 5 martie 2016 10:45:07
Problema Stramosi Scor 80
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.05 kb
#include <fstream>
#include <cstdio>
using namespace std;

ofstream g("stramosi.out");

long n,m,i,j,p,nr,q,dp[250005][30];


long stramos(long q,long p)
{
    long P=1,nr=0;
    while (true)
    {
        nr=0;
        P=1;
        if (q==0)
            return 0;
        while (P<<1<=p)
        {
            P<<=1;
            nr++;
        }
        if (P==p)
            return dp[q][nr];
        q=dp[q][nr];
        p=p-P;
    }
}

int main()
{
    freopen("stramosi.in","r",stdin);
    scanf("%ld%ld",&n,&m);
    for (i=1;i<=n;i++)
        scanf("%ld",&dp[i][0]);

    p=1;
    while (p<<1<=n)
    {
        p<<=1;
        nr++;
    }

    p=0;

    long ok;
    for (j=1;j<=nr;j++)
    {
        ok=0;
        for (i=1;i<=n;i++)
        {
            dp[i][j]=dp[dp[i][j-1]][j-1];
            if (dp[i][j]!=0)
                ok=1;
        }
        if (ok==0)
            break;
    }
    for (i=1;i<=m;i++)
    {
        scanf("%ld%ld",&q,&p);
        g<<stramos(q,p)<<'\n';
    }
    return 0;
}