Cod sursa(job #2272131)

Utilizator marcudanfDaniel Marcu marcudanf Data 29 octombrie 2018 18:38:54
Problema Stramosi Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.82 kb
#include <fstream>
#include <cmath>
using namespace std;
ifstream fin("stramosi.in");
ofstream fout("stramosi.out");
const int NMax = 250000;
int A[20][NMax + 5];
int Log2[NMax + 5];
int N,M;
void Read()
{
    fin >> N >> M;
    for(int i = 1; i <= N; ++i)
        fin >> A[0][i];
}

void Precalculate()
{
    for(int i = 2; i <= N; i++){
        Log2[i] = 1 + Log2[i/2];
    }
    for(int i = 1; (1<<i) <= N; ++i)
        for(int j = 1; j <= N; ++j)
            A[i][j] = A[i-1][A[i-1][j]];
}
int Find(int Q, int P)
{
    while(P)
    {
        int K = Log2[P];
        Q = A[K][Q];
        P = P - (1<<K);
    }
    return Q;
}

int main()
{
    Read();
    Precalculate();
    while(M--)
    {
        int Q,P;
        fin >> Q >> P;
        fout << Find(Q,P)<<"\n";
    }
    return 0;
}