Cod sursa(job #2669862)

Utilizator Tudor_PascaTudor Pasca Tudor_Pasca Data 8 noiembrie 2020 11:37:05
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

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

const int INF = 0x3f3f3f3f3f3f3f3f;
int n, t;
int log2[100100], rmq[100100][20];

void logCalc()
{
    log2[1] = 0;

    for(int i = 2; i <= n; i++)
        log2[i] = log2[i / 2] + 1;
}

void rangeCalc()
{
    for(int j = 1; (1 << j) <= n; j++)
        for(int i = 1; i + (1 << j) <= n + 1; i++)
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
}

int query(int x, int y)
{
    int dist = y - x + 1;

    return min(rmq[x][log2[dist]], rmq[y - (1 << log2[dist]) + 1][log2[dist]]);
}

int main()
{
    in >> n >> t;

    memset(rmq, INF, sizeof rmq);

    for(int i = 1; i <= n; i++)
        in >> rmq[i][0];

    logCalc();

    rangeCalc();

    while(t--)
    {
        int x, y;
        in >> x >> y;

        out << query(x, y) << '\n';
    }

    return 0;
}