Cod sursa(job #1665322)

Utilizator mihai.constantinConstantin Mihai mihai.constantin Data 26 martie 2016 20:24:46
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <iostream>
#include <fstream>
using namespace std;

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

const int N_max = 100005;
const int Log = 18;

int v[N_max];

int log[N_max];

int rmq[N_max][Log];

int N, Q;

int minim(int x, int y)
{
    if(x < y) return x;
    else
        return y;
}

void read()
{
    in >> N >> Q;

    for(int i = 1; i <= N; i++) in >> v[i];
}

void solve()
{
    int i, j;

    log[1] = 0;
    for(i = 2; i <= N; i++) log[i] = log[i / 2] + 1;

    for(i = 1; i <= N; i++) rmq[i][0] = v[i];

    for(i = 1; i <= N; i++)
        for(j = 1; (1 << j) <= i; j++)
        {
            int k = i - (1 << (j - 1));

            rmq[i][j] = minim(rmq[i][j - 1], rmq[k][j - 1]);
        }
}

void write()
{
    int i, a, b;

    for(i = 1; i <= Q; i++)
    {
        in >> a >> b;

        int l = log[b - a + 1];

        int ans = minim(rmq[b][l], rmq[a + (1 << l) - 1][l]);

        out << ans << '\n';
    }
}

int main()
{
    read();
    solve();
    write();

    return 0;
}