Cod sursa(job #770915)

Utilizator SchumiDumitru Andrei Georgian Schumi Data 24 iulie 2012 11:30:02
Problema Stramosi Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.04 kb
#include <cstdio>
#include <fstream>
#include <cmath>
#include <string>
using namespace std;

const int N = 250005;

int n, m, dim, x, y, sol;
int tata[N];
int stramosi[18][N];
string s;


int main()
{
    freopen ("stramosi.in", "r", stdin);
    freopen ("stramosi.out", "w", stdout);
    scanf("%d %d", &n, &m);
    for(int i = 1; i <= n; ++i) {
        scanf("%d", &tata[i]);
        stramosi[0][i] = tata[i];
    }
    
    dim = ceil(log2(n));
    for(int i = 1; i <= dim; ++i)
        for(int j = 1; j <= n; ++j)
            stramosi[i][j] = stramosi[i - 1][stramosi[i - 1][j]];
    for(int i = 0; i <= dim; ++i) {
        for(int j = 0; j <= n; ++j) {
            fprintf(stderr, "%d ", stramosi[i][j]);
        }
        fprintf(stderr, "\n");
    }

    for(int i = 1; i <= m; ++i) {
        scanf("%d %d", &x, &y);
        int k = 0;
        while((1 << (k + 1)) < y)
            ++k;
        sol = stramosi[k][x];
        for(int j = 1; j <= (y - (1 << k)) ; ++j)
            sol = tata[sol];
        printf("%d\n", sol);
    }
    
    return 0;
}