Cod sursa(job #2753848)

Utilizator icnsrNicula Ionut icnsr Data 24 mai 2021 16:27:55
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include <fstream>
std::ifstream fin("rmq.in");
std::ofstream fout("rmq.out");

#include <array>

int main()
{

        unsigned n, m;
        fin >> n >> m;

        std::array<unsigned, 100006> arr = {};
        for(unsigned i = 1; i <= n; ++i)
        {
                fin >> arr[i];
        }

        std::array<unsigned, 100006> log2;
        log2[1] = 0;
        for(unsigned i = 2; i <= n; ++i)
        {
                log2[i] = log2[i / 2] + 1;
        }

        std::array<std::array<unsigned, 100006>, 18> rmq = {};
        for(unsigned i = 1; i <= n; ++i)
        {
                rmq[0][i] = arr[i];
        }

        for(unsigned i = 1; (1u << i) <= n; ++i)
        {
                for(unsigned j = 1; j <= n - (1 << i) + 1; ++j)
                {
                        rmq[i][j] = std::min(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]);
                }
        }

        for(unsigned i = 0; i < m; ++i)
        {
                unsigned a, b;
                fin >> a >> b;

                const unsigned diff = b - a + 1;
                const unsigned logdiff = log2[diff];
                const unsigned nums_left = diff - (1 << logdiff);
                fout << std::min(rmq[logdiff][a], rmq[logdiff][a + nums_left]) << '\n';
        }
}