Cod sursa(job #2253809)

Utilizator toadehuPuscasu Razvan Stefan toadehu Data 4 octombrie 2018 14:23:04
Problema Cautare binara Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.7 kb
#include <bits/stdc++.h>

using namespace std;

long long int n,v[1000019],m;

int caut0 (int val)
{
    int nr=log2(n);
    ++nr;
    int step=(1<<nr);
    //fout<<"step="<<step<<"\n";
    int cpos=1;
    while (step>0)
    {
        if (cpos+step<=n && v[cpos+step]<=val)
        {
            cpos+=step;
        }
        step/=2;
    }
    return cpos;
}

int caut1 (int val)
{
    int nr=log2(n);
    ++nr;
    int step=(1<<nr);
    int cpos=1;
    while (step>0)
    {
        if (cpos+step<=n && v[cpos+step]<=val)
        {
            cpos+=step;
        }
        step/=2;
    }
    return cpos;
}

int caut2 (int val)
{
    int nr=log2(n);
    ++nr;
    int step=(1<<nr);
    int cpos=1;
    while (step>0)
    {
        if (cpos+step<=n && v[cpos+step]<val)
        {
            cpos+=step;
        }
        step/=2;
    }
    return cpos+1;
}

int main()
{
    ifstream fin ("cautbin.in");
    ofstream fout ("cautbin.out");
    fin>>n;
    for (int i=1; i<=n; ++i)
    {
        fin>>v[i];
    }
    fin>>m;
    for (int i=1; i<=m; ++i)
    {
        int p,nr;
        fin>>p>>nr;
        switch (p)
        {
        case 0:
            if (v[caut0(nr)]==nr)
            {
                fout<<caut0(nr)<<"\n";
            }
            else
            {
                fout<<-1<<"\n";
            }
            break;
        case 1:
            if (v[caut1(nr)]<=nr)
            {
                fout<<caut1(nr)<<"\n";
            }
            break;
        case 2:
            if (v[caut2(nr)]>=nr)
            {
                fout<<caut2(nr)<<"\n";
            }
            break;
        }
    }
    return 0;
}