Cod sursa(job #1415620)

Utilizator alex1096Postolache Alex alex1096 Data 5 aprilie 2015 16:02:46
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.8 kb
#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
int n,m,v[100001],a[100001][18],x,y,k;
void build()
{
    for(int i=0;i<n;++i)
        a[i][0]=i;
    for(int j=1;(1<<j)<n;++j)
        for(int i=0;i+(1<<j)-1<n;++i)
    {
        if(v[a[i][j-1]] <v[a[i+(1<<(j-1))][j-1]])
            a[i][j]=a[i][j-1];
        else
            a[i][j]=a[i+(1<<(j-1))][j-1];
    }
}

int main()
{
    ifstream fin("rmq.in");
    ofstream fout("rmq.out");

    fin>>n>>m;
    for(int i=0;i<n;++i)
        fin>>v[i];
    build();


    while(m--)
    {
        fin>>x>>y;
        x--;
        y--;

        k=log2(y-x+1);
        if(v[a[x][k]] < v[a[y-(1<<k)+1][k]])
           fout<<v[a[x][k]]<<"\n";
        else fout<<v[a[y-(1<<k)+1][k]]<<"\n";
    }
    return 0;
}