Cod sursa(job #3215725)

Utilizator Kawaiimeatball13Russu Mihaela Kawaiimeatball13 Data 15 martie 2024 12:12:54
Problema Range minimum query Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.19 kb
#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

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

int n, m;
int a[100001];
int rmq[100001][20];

void citire()
{
    fin >> n >> m;
    for(int i = 1; i <= n; ++i)
    {
        fin >> a[i];
        rmq[0][i] = a[i];
    }

}

void precalc()
{
    int putere = log2(n);
    int p = 2;
    for(int i = 1; i <= putere; ++i)
    {
        for(int j = 1; j <= n - p + 1; ++j)
        {
            int cu_cat = p / 2;
            rmq[i][j] = min(rmq[i - 1][j], rmq[i - 1][j + cu_cat]);
        }
        p *= 2;
    }
}

int laN(int a, int p)
{
    int rez = 1;
    while(p)
    {
        if(p % 2 == 1)
        {
            rez *= a;
            p--;
        }
        else
        {
            a *= a;
            p /= 2;
        }

    }

    return rez;
}

int query(int x, int y)
{
    int i = log2(y - x + 1);
    int p = laN(2, i);

    return min(rmq[i][x], rmq[i][y - p + 1]);
}

int main()
{
    citire();
    precalc();

    int x, y;
    for(int i = 0; i < m; ++i)
    {
        fin >> x >> y;
        fout << query(x, y) << '\n';
    }
    return 0;
}