Cod sursa(job #428711)

Utilizator hendrikHendrik Lai hendrik Data 29 martie 2010 14:57:06
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.19 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[18][250010],Q,P,now,x;

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

void get_int(int &a){
    char c;
    while (c=getchar()){
        if (c>='0' && c<='9'){
            a=c-'0';
            break;
        }
    }
    while (c=getchar()){
        if (c>='0' && c<='9'){
            a=(a<<1)+(a<<3)+(c-'0');
        }
        else break;
    }
}

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