Cod sursa(job #1456577)

Utilizator CollermanAndrei Amariei Collerman Data 1 iulie 2015 11:35:58
Problema Range minimum query Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>
#include <cmath>
using namespace std;
ofstream fout("rmq.out");
ifstream fin("rmq.in");
const int NMAX = 100005;

int n, m;
int v[NMAX];
int st[NMAX][19]; // Sparse Table

void read()
{
    fin >> n >> m;
    for(int i=1; i<=n; i++) fin >> v[i];
}

void create_table()
{
    for(int i=1; i<=n; i++)
        st[i][0] = i;

    for(int j = 1; (1 << j) <= n; j++)
        for(int i = 1; i <= n; i++)
            if(v[st[i][j - 1]] < v[st[i + (1 << (j - 1))][j - 1]])
                st[i][j] = st[i][j - 1];
            else
                st[i][j] = st[i + (1 << (j - 1))][j - 1];
}

void find_minimum(int i, int j)
{
    int k = log2(j - i + 1);

    if(v[st[i][k]] <= v[st[j - (1 << k) + 1][k]])
        fout << v[st[i][k]] << '\n';
    else
        fout << v[st[j - (1 << k) + 1][k]] << '\n';
}

void rmq()
{
    int x, y;

    for(int i=1; i<=m; i++) {
        fin >> x >> y;
        find_minimum(x, y);
    }
}

int main()
{
    read();
    create_table();
    rmq();

    fout.close();
    fin.close();
    return 0;
}