Cod sursa(job #2575650)

Utilizator halexandru11Hritcan Alexandru halexandru11 Data 6 martie 2020 14:52:35
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.19 kb
#include <bits/stdc++.h>

using namespace std;

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

const int nax = 1e5 + 5;

int arb[nax][20];
int lg[nax];
int n, m;

void Read()
{
    int i;
    f >> n >> m;
    for(i = 0; i < n; ++i)
        f >> arb[i][0];
}

void Processing()
{
    int i, j;

    lg[1] = 0;
    for(i = 2; i < n; ++i)
        lg[i] = lg[i >> 1] + 1;

    for(j = 1; (1 << j) <= n; ++j)
        for(i = 0; i + (1 << j) - 1 < n; ++i)
            arb[i][j] = min (arb[i][j-1], arb[i + (1 << (j-1))][j-1]);
}

int Rmq(int& st, int& dr)
{
    if(st > dr)
    {
        st ^= dr;
        dr ^= st;
        st ^= dr;
    }

    int range = dr - st + 1;
    int power = lg[range];
    return min(arb[st][power], arb[dr - (1 << power) + 1][power]);
}

int main()
{
    ios_base::sync_with_stdio(false);
    Read();
    Processing();

    int i, x, y;
    for(i = 1; i <= m; ++i)
    {
        f >> x >> y;
        --x; --y;
        g << Rmq(x, y) << "\n";
    }

//    for(int i = 0; i < n; ++i)
//    {
//        for(int j = 0; j < lg[n-i] + 1; ++j)
//            cout << arb[i][j] << " ";
//        cout << "\n";
//    }
    return 0;
}