Cod sursa(job #2939443)

Utilizator Matei_MunteanuMunteanu Matei Ioan Matei_Munteanu Data 13 noiembrie 2022 18:18:20
Problema Range minimum query Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.16 kb
#include <bits/stdc++.h>
using namespace std;
const int NMAX = 100004;
const int K = 25;

ifstream fin("rmq.in");
ofstream fout("rmq.out");

long long n, q;
vector<long long> A;
long long st[K + 1][NMAX + 4];

long long log2_floor(long long x)
{
    long long rez = (log(x) / log(2));
    if (x == (1 << rez))
    {
        rez--;
    }
    return rez;
}

void precomputation()
{
    copy(A.begin(), A.end(), st[0]);
    for (int i = 1; i <= K; i++)
    {
        for (int j = 0; (j + (1 << i) - 1) < n; j++)
        {
            st[i][j] = min(st[i - 1][j], st[i - 1][j + (1 << (i - 1))]);
        }
    }
}

long long minimum(long long left, long long right)
{
    long long i = log2_floor(right - left + 1);
    long long mini = min(st[i][left], st[i][right - (1 << i) + 1]);
    return mini;
}

int main()
{
    fin >> n >> q;
    for (int i = 1; i <= n; i++)
    {
        int x;
        fin >> x;
        A.push_back(x);
    }
    precomputation();
    for (int i = 1; i <= q; i++)
    {
        long long left, right;
        fin >> left >> right;
        fout << minimum(left - 1, right - 1) << '\n';
    }
    return 0;
}