Cod sursa(job #1373933)

Utilizator diana97Diana Ghinea diana97 Data 4 martie 2015 21:30:30
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <iostream>
#include <fstream>

using namespace std;

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

const int NMAX = 100000 + 1;
const int LOGMAX = 17;

int n, q;
int lg2[NMAX], rmq[LOGMAX][NMAX];

void citeste() {
    f >> n >> q;
    for (int i = 1; i <= n; i++) f >> rmq[0][i];
}

void precalculeaza() {
    int l;
    for (int i = 2; i <= n; i++)
        lg2[i] = lg2[i / 2] + 1;

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

void raspunde() {
    int a, b, l, dif, secv1, secv2;
    for (int i = 1; i <= q; i++) {
        f >> a >> b;
        dif = b - a + 1;
        l = lg2[dif];
        secv1 = a;
        secv2 = a + dif - (1 << l);
        g << min(rmq[l][secv1], rmq[l][secv2]) << '\n';
    }
}

int main() {
    citeste();
    precalculeaza();
    raspunde();
}