Cod sursa(job #2197354)

Utilizator LivcristiTerebes Liviu Livcristi Data 21 aprilie 2018 21:23:54
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <fstream>
#include <iostream>
#include <cmath>
#define NUM 100005
#define LGNUM 17
int mat[NUM][LGNUM];
int v[NUM];
int n, m, x, y;
using namespace std;
void init_mat()
{
    for(int i = 0; i < n; ++i)
        mat[i][0] = i;

    for(int j = 1; (1 << j) < n; ++j)
    {
        for(int i = 0; (i + (1 << j) - 1) < n; ++i)
        {
            if(v[mat[i][j - 1]] < v[mat[i + (1 << (j - 1))][j - 1]])
                mat[i][j] = mat[i][j - 1];
            else
                mat[i][j] = mat[i + (1 << (j - 1))][j - 1];
        }
    }
}
int query(int st, int dr)
{
    int j = log2(dr - st + 1);
    if(v[mat[st][j]] < v[mat[dr - (1 << j) + 1][j]])
        return mat[st][j];
    else
        return mat[dr - (1 << j) + 1][j];
}
int main()
{
    ifstream f("rmq.in");
    ofstream g("rmq.out");

    f >> n >> m;
    for(int i = 0; i < n; ++i)
        f >> v[i];
    init_mat();
    for(int i = 0; i < m; ++i)
    {
        f >> x >> y;
        g << v[query(x - 1, y - 1)] << "\n";
    }
    f.close();
    g.close();
}