Cod sursa(job #1075885)

Utilizator Iustin_BulimarFMI Iustin Bulimar Iustin_Bulimar Data 9 ianuarie 2014 18:13:30
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.81 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=17;

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

void rmq(int v[], int n)
{
    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++)
            if(v[m[i][j-1]]<v[m[i+(1<<(j-1))][j-1]]) m[i][j]=m[i][j-1];
            else m[i][j]=m[i+(1<<(j-1))][j-1];
}

int query(int v[], int x, int y)
{
    int k=log2(y-x+1);
    if(v[m[x-1][k]]<v[m[y-(1<<k)][k]]) return v[m[x-1][k]];
    return v[m[y-(1<<k)][k]];
}

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