Cod sursa(job #2207790)

Utilizator EclipseTepes Alexandru Eclipse Data 26 mai 2018 20:04:16
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <iostream>
#include <fstream>
#include <math.h>
#include <cmath>
#define dMAX 100000

using namespace std;

int n, m;
int x, y;
int arr[dMAX + 2];
int sparseTable[dMAX][(int)log2(dMAX) + 1];

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

void MakeTable() {
    int i, j;
    for (j = 1; (1 << j) <= n; j++) {
        for (i = 1; i + (1 << j) - 1 <= n; i++) {
            if (arr[sparseTable[i][j - 1]] < arr[sparseTable[i + (1 << (j - 1))][j - 1]]) {
                sparseTable[i][j] = sparseTable[i][j - 1];
            } else
                sparseTable[i][j] = sparseTable[i + (1 << (j - 1))][j - 1];
        }
    }
}

int RMQ(int low, int r) {
    int l = r - low + 1;
    int k = (int)log2(l);
    return min(arr[sparseTable[low][k]], arr[sparseTable[low + l - (1 << k)][k]]);
}

int main()
{
    int i, j;
    fin >> n >> m;
    for (i = 1; i <= n; i++) {
        fin >> arr[i];
        sparseTable[i][0] = i;
    }
    MakeTable();
    for (i = 1; i <= m; i++) {
        fin >> x >> y;
        fout << RMQ(x, y) << '\n';
    }
    return 0;
}