Cod sursa(job #1749746)

Utilizator cristiandarlaDarla Cristian cristiandarla Data 28 august 2016 17:48:25
Problema Range minimum query Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <bits/stdc++.h>
using namespace std;
int d[17][100002],m,n,q;
ifstream f("rmq.in");
ofstream g("rmq.out");

int putere2(int n)//calculez 2^n
{
    if(n==0)
        return 1;
    else
        return 2*putere2(n-1);
}

int exponent(int n)//calculez x astfel incat 2^x<=n
{
    int x=0,p=1;
    while(p<n)
    {
        x++;
        p<<=1;
    }
    if(p>n)
        x--;
    return x;
}

void afis()
{
    int i,j;
    for(i=0;i<=m;i++)
    {
        for(j=1;j<=n && d[i][j];j++)
            cout<<d[i][j]<<" ";
        cout<<'\n';
    }
}

int rmq(int x,int y)
{
    int k=exponent(y-x);
    return min(d[k][x],d[k][y-putere2(k)+1]);
}

void constructie()
{
    int i,j,dist;
    f>>n>>q;
    for(i=1;i<=n;i++)
        f>>d[0][i];
    m=exponent(n);
    for(i=1;i<=m;i++)
    {
        dist=putere2(i-1);
        for(j=1;j<=n-dist+1;j++)
            d[i][j]=min(d[i-1][j],d[i-1][j+dist]);
    }
    //afis();
    int x,y;
    for(i=1;i<=q;i++)
    {
        f>>x>>y;
        g<<rmq(x,y)<<'\n';
    }
}

int main()
{
    constructie();
    return 0;
}