Cod sursa(job #2576286)

Utilizator MarianConstantinMarian Constantin MarianConstantin Data 6 martie 2020 18:19:57
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.84 kb
#include <bits/stdc++.h>

using namespace std;

ifstream fin("rmq.in");
ofstream fout("rmq.out");
const int MAXN = 100005, LOG = 20;

int lg[MAXN], dp[LOG][MAXN], inp[MAXN], n, m;

void preprocess()
{
    for (int i = 2; i <= n; ++i)
        lg[i] = lg[i >> 1] + 1;
    for (int i = 1; i <= n; ++i)
        dp[0][i] = inp[i];
    for (int i = 1; i <= lg[n]; ++i)
        for (int j = 1; j <= n; ++j)
            dp[i][j] = min(dp[i - 1][j], dp[i - 1][j + (1 << (i - 1))]);
}

int query(int x, int y)
{
    int k = lg[y - x + 1];
    return min(dp[k][x], dp[k][y - (1 << k) + 1]);
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= n; ++i)
        fin >> inp[i];
    preprocess();
    for (int i = 0; i < m; ++i) {
        int x, y;
        fin >> x >> y;
        fout << query(x, y) << '\n';
    }
    return 0;
}