Cod sursa(job #428639)

Utilizator hendrikHendrik Lai hendrik Data 29 martie 2010 14:03:31
Problema Stramosi Scor 90
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.88 kb
#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;

void open(){
    freopen("stramosi.in","r",stdin);
    freopen("stramosi.out","w",stdout);
}

int n,m,par[250010][18],Q,P,now,x;

int log_2(int a){
    int i=1;
    for (;(1<<i)<=a;i++);
    return i-1;
}

int main(){
    open();
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++){
        scanf("%d",&par[i][0]);
    }
    for (int i=1;(1<<i)<=n;i++){
        for (int j=1;j<=n;j++){
            par[j][i]=par[par[j][i-1]][i-1];
        }
    }
    x=log_2(n);
    for (int i=0;i<m;i++){
        scanf("%d%d",&Q,&P);
        now=Q;
        for (int j=x;j>=0;j--){
            if (P>=(1<<j)){
                now=par[now][j];
                P-=(1<<j);
            }
        }
        printf("%d\n",now);
    }
    //system("pause");
    return 0;
}