Cod sursa(job #1050676)

Utilizator Iustin_BulimarFMI Iustin Bulimar Iustin_Bulimar Data 8 decembrie 2013 22:45:02
Problema Range minimum query Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.8 kb
#include <fstream>
#include <cmath>
using namespace std;
ifstream cin("rmq.in");
ofstream cout("rmq.out");

const int n_max=100001;
const int log_n_max=20;

int n, q, i, v[n_max], m[n_max][log_n_max], k, x, y;

int loga(int x)
{
    int i;
    for(i=1; 1<<i<=x; i++);
    return --i;
}

bool comp(int x, int y)
{
    return (v[x]<v[y]);
}

void rmq()
{
    int i, j;
    for(i=0; i<n; i++) m[i][0]=i;
    for(j=1; 1<<j<=n; j++)
        for(i=0; i+(1<<j)-1<n; i++)
            m[i][j]=min(m[i][j-1], m[i+(1<<(j-1))][j-1], comp);
}

int main()
{
    cin>>n>>q;
    for(i=0; i<n; i++) cin>>v[i];
    rmq();
    for(i=1; i<=q; i++)
    {
        cin>>x>>y;
        x--; y--;
        k=loga(y-x+1);
        cout<<min(v[m[i][k]], v[m[y-(1<<k)+1][k]])<<'\n';
    }
    return 0;
}