Cod sursa(job #3301303)

Utilizator bogdan1479Luca Bogdan Alexandru bogdan1479 Data 24 iunie 2025 15:02:35
Problema Stramosi Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 3.33 kb
#include <fstream>

using namespace std;

const int NMAX = 250001, LOG2 = 21;

class InParser
{
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch()
    {
        ++sp;
        if(sp == 4096)
        {
            sp = 0;
            fread(buff, 1, 4096, fin);
        }
        return buff[sp];
    }

public:
    InParser(const char* nume)
    {
        fin = fopen(nume, "r");
        buff = new char[4096]();
        sp = 4095;
    }

    InParser& operator >> (int &n)
    {
        char c;
        while(!isdigit(c = read_ch()) && c != '-');
        int sgn = 1;
        if(c == '-')
        {
            n = 0;
            sgn = -1;
        }
        else
        {
            n = c - '0';
        }
        while(isdigit(c = read_ch()))
        {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }

    InParser& operator >> (long long &n)
    {
        char c;
        n = 0;
        while(!isdigit(c = read_ch()) && c != '-');
        long long sgn = 1;
        if(c == '-')
        {
            n = 0;
            sgn = -1;
        }
        else
        {
            n = c - '0';
        }
        while(isdigit(c = read_ch()))
        {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }
};

class OutParser
{
private:
    FILE *fout;
    char *buff;
    int sp;

    void write_ch(char ch)
    {
        if(sp == 50000)
        {
            fwrite(buff, 1, 50000, fout);
            sp = 0;
            buff[sp++] = ch;
        }
        else
        {
            buff[sp++] = ch;
        }
    }


public:
    OutParser(const char* name)
    {
        fout = fopen(name, "w");
        buff = new char[50000]();
        sp = 0;
    }
    ~OutParser()
    {
        fwrite(buff, 1, sp, fout);
        fclose(fout);
    }

    OutParser& operator << (int vu32)
    {
        if(vu32 <= 9)
        {
            write_ch(vu32 + '0');
        }
        else
        {
            (*this) << (vu32 / 10);
            write_ch(vu32 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (long long vu64)
    {
        if(vu64 <= 9)
        {
            write_ch(vu64 + '0');
        }
        else
        {
            (*this) << (vu64 / 10);
            write_ch(vu64 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (char ch)
    {
        write_ch(ch);
        return *this;
    }
    OutParser& operator << (const char *ch)
    {
        while(*ch)
        {
            write_ch(*ch);
            ++ch;
        }
        return *this;
    }
};

InParser fin("stramosi.in");
OutParser fout("stramosi.out");

int n, m, t[LOG2][NMAX], lg[NMAX];

void citire()
{
    fin >> n >> m;
    lg[0] = -1;
    for(int i = 1; i <= n; ++i)
    {
        lg[i] = lg[i >> 1] + 1;
        fin >> t[0][i];
    }
    for(int k = 1; (1 << k) <= n; ++k)
        for(int i = 1; i <= n; ++i)
            t[k][i] = t[k - 1][t[k - 1][i]];
}

void query()
{
    int q, p;
    fin >> q >> p;
    while(p > 0)
    {
        q = t[lg[p]][q];
        p -= (1 << lg[p]);
    }
    fout << q << '\n';
}

int main()
{
    citire();
    while(m--) query();
    return 0;
}