Cod sursa(job #3235333)

Utilizator AndreiLeusteanLeustean Andrei AndreiLeustean Data 17 iunie 2024 07:35:08
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.05 kb
#include <iostream>
#include <cmath>
#include <fstream>
using namespace std;

const int NMAX = 100001;
const int LMAX = 20;

int lg[NMAX];

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

void createLog()
{
    lg[1] = 0;
    for (int i = 2; i < NMAX; i++)
        lg[i] = lg[i / 2] + 1;
}

void preprocRMQ(int rmq[][LMAX], int a[NMAX], int n)
{
    for (int i = 0; i < n; i++)
        rmq[i][0] = a[i];

    for (int j = 1; (1 << j) <= n; j++)
        for (int i = 0; i + (1 << j) - 1 < n; i++)
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
}

int query(int x, int y, int rmq[][LMAX])
{
    int k = lg[y - x + 1];
    return min(rmq[x][k], rmq[y - (1 << k) + 1][k]);
}

int rmq[NMAX][LMAX], v[NMAX];

int main()
{
    createLog();

    int n, m;
    in >> n >> m;
    for (int i = 0; i < n; i++)
        in >> v[i];
    preprocRMQ(rmq, v, n);
    for (int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        out << query(x - 1, y - 1, rmq) << endl;
    }
    return 0;
}