Cod sursa(job #2145014)

Utilizator tanasaradutanasaradu tanasaradu Data 27 februarie 2018 01:01:10
Problema Range minimum query Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin ("rmq.in");
ofstream fout ("rmq.out");
const int Nmax =  100005;
const short LOG2 = 17;
int p2[LOG2] , n , rmq[LOG2][Nmax] , Q;
/// rmq[i][j] - minimul din intervalul [j - 2 ^ i + 1 , j]
int main()
{
    int x , y , k;
    fin >> n >> Q;
    for(int i = 1 ; i <= n ; i++)
    {
        fin >> x;
        rmq[0][i] = x;
    }
    p2[1] = 0;
    for(int i = 2 ; i <= n ; i++)
        p2[i] = p2[i / 2] + 1;
    for(int i = 1 ; (1 << i) <= n ; i++)
        for(int j = (1 << i) ; j <= n; j++)
    {
        /// impartim intervalul [j - 2 ^ i + 1 , j] in doua intervale
        ///[j - (2 ^(i - 1)) + 1 , j] , [j - 2 ^ i + 1 , j - 2 ^ (i - 1)]
        rmq[i][j] = min(rmq[i - 1][j] , rmq[i - 1][j - (1 << (i - 1))]);
    }
    while(Q -- )
    {
        fin >> x >> y;
        k = p2[y - x + 1];
        fout << min(rmq[k][y] , rmq[k][x + (1 << k) - 1]) << "\n";
    }
    fin.close();
    fout.close();
    return 0;
}