Cod sursa(job #1320648)

Utilizator eneandradaEne Oana-Andrada eneandrada Data 18 ianuarie 2015 11:29:55
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <iostream>
#include <fstream>
#include <cstdio>
using namespace std;




int A,poz,Arb[1<<18],B,mx,val;

void modif(int nod, int st, int dr) //in arbore pune pe pozitia poz valoarea val apoi reactualizeaza maximele
{
    if (st==dr)
    {
        Arb[nod]=val;
        return;
    }
    int mij=(st+dr)>>1;
    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(Arb[nod]>mx)
            mx=Arb[nod];
        return;
    }
    int mij=(st+dr)>>1;
    if(A<=mij)
        maxim(2*nod,st,mij);
    if(mij<B)
        maxim(2*nod+1,mij+1,dr);
}


int main()
{
    int a,M,N,i,op,b,x;
    freopen("arbint.in", "r", stdin);
    freopen("arbint.out", "w",stdout);
    scanf("%d%d", &N, &M);
    for(i=1;i<=N;i++)
    {
        scanf("%d", &x);
        poz=i; val=x;
        modif(1,1,N);
    } //se construieste arborele valorilor maxime de pe fiecare interval
    for(i=1;i<=M;i++)
    {
        scanf("%d%d%d", &op,&a,&b);
        if(op==0)
        {
            mx=-1;
            A=a; B=b;
            maxim(1,1,N);
            printf("%d\n", mx);
        }
        else
        {
            poz=a; val=b;
            modif(1,1,N);
        }
    }
    return 0;
}