Cod sursa(job #2939458)

Utilizator Matei_MunteanuMunteanu Matei Ioan Matei_Munteanu Data 13 noiembrie 2022 18:33:03
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <bits/stdc++.h>
using namespace std;
const int NMAX = 100000;
const int K = 18;

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

int n, q;
int A[100004];
int st[18][100004];
int lg2[100004];

void log2_floor()
{
    lg2[1] = 0;
    for (int i = 2; i <= 100004; i++)
    {
        lg2[i] = 1 + lg2[i / 2];
    }
}

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

int minimum(int left, int right)
{
    int i = lg2[right - left + 1];
    int mini = min(st[i][left], st[i][right - (1 << i) + 1]);
    return mini;
}

int main()
{
    log2_floor();
    fin >> n >> q;
    for (int i = 1; i <= n; i++)
    {
        fin >> A[i];
    }
    precomputation();
    for (int i = 1; i <= q; i++)
    {
        int left, right;
        fin >> left >> right;
        fout << minimum(left, right) << '\n';
    }
    return 0;
}