Cod sursa(job #1139141)

Utilizator manutrutaEmanuel Truta manutruta Data 10 martie 2014 21:30:09
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <iostream>
#include <fstream>

using namespace std;

#define MAXN 100005
#define MAXLG 18

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

int n;
int rmq[MAXLG][MAXN];

int lg(int nr)
{
    int sol = 1;
    for (; (1 << sol) <= nr; sol++);
    return sol - 1;
}

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

int query(int x, int y)
{
    if (x == y) {
        return rmq[0][x];
    }

    int sz = lg(y - x + 1);

    return min(rmq[sz][x], rmq[sz][y - (1 << sz) + 1]);
}

int main()
{
    int m;
    f >> n >> m;
    for (int i = 1; i <= n; i++) {
        f >> rmq[0][i];
    }

    precompute();

    for (int j = 1; j <= m; j++) {
        int x, y;
        f >> x >> y;
        g << query(x, y) << '\n';
    }

    f.close();
    g.close();
    return 0;
}