Cod sursa(job #828405)

Utilizator alexalghisiAlghisi Alessandro Paolo alexalghisi Data 3 decembrie 2012 18:57:07
Problema Range minimum query Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;

int a[20][100005],n,m,minim; /// i = lungime ; j = poz
int p2[20];

void gen()
{
    p2[0]=1;
    for(int i=1;i<=20;++i)
        p2[i]=2*p2[i-1];
    for(int i=1;i<=16;++i)
    {
        for(int j=1;j<=n;++j)
            a[i][j]=min(a[i-1][j],a[i-1][j+(1<<(i-1))]);
    }
    return;
}
int caut(int x)
{
    int left=0,right=20,rez;
    while(left<=right)
    {
        int mij=(left+right)/2;
        if(p2[mij]<=x)
            {
                rez=mij;
                left=mij+1;
            }
        else
            right=mij-1;
    }
    return rez;
}
void rez(int poz_start,int lungime)
{
    int i=caut(lungime);

    minim=min(minim,a[i][poz_start]);
    lungime-=p2[i];
    if(lungime)
        rez(poz_start+p2[i],lungime);

}

int main()
{
    ifstream f("rmq.in");
    ofstream g("rmq.out");
    f>>n>>m;
    for(int i=1;i<=n;++i)
        f>>a[0][i];
    gen();
    for(int i=1;i<=m;++i)
    {
        minim=1<<30;
        int a,b;
        f>>a>>b;
        rez(a,b-a+1);
        g<<minim<<"\n";
    }
    return 0;
}