Cod sursa(job #1320429)

Utilizator eneandradaEne Oana-Andrada eneandrada Data 17 ianuarie 2015 23:05:28
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

int M,N,a,poz,i,op;
long long Arb[1<<18],b,x,mx,val;

void modif(int nod, int st, int dr) //in arbore pune pe pozitia poz valoarea val
{
    if (st==dr)
    {
        Arb[nod]=val;
        return;
    }
    int mij=(st+dr)/2;
    if(poz<=mij)
        modif(2*nod,st,mij);
    else
        modif(2*nod+1,mij+1,dr);
    Arb[nod]=max(Arb[2*nod],Arb[2*nod+1]);
}

void maxim(int nod, int st, int dr) //extrage din arbore maximul dintre pozitiile a si b
{
    if(a<=st && dr<=b)
    {
        if(mx<Arb[nod])
            mx=Arb[nod];
        return;
    }
    int mij=(st+dr)/2;
    if(a<=mij)
        maxim(2*nod,st,mij);
    if(mij<b)
        maxim(2*nod+1,mij+1,dr);
}


int main()
{
    f>>N>>M;
    for(i=1;i<=N;i++)
    {
        f>>x;
        poz=i; val=x;
        modif(1,1,N);
    } //se construieste arborele prin inserarea fiecarui element
    for(i=1;i<=M;i++)
    {
        f>>op>>a>>b;
        if(op==0)
        {
            mx=-1;
            maxim(1,1,N);
            g<<mx; g<<endl;
        }
        else
        {
            poz=a; val=b;
            modif(1,1,N);
        }
    }
    f.close(); g.close();
    return 0;
}