Cod sursa(job #388110)

Utilizator DraStiKDragos Oprica DraStiK Data 29 ianuarie 2010 12:55:22
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include <algorithm>
using namespace std;

#define DIM 100005

int aint[3*DIM];
int n,q,maxim;

void update (int nod,int st,int dr,int poz,int val)
{
    int mij;

    if (st==dr)
        aint[nod]=val;
    else
    {
        mij=(st+dr)/2;
        if (poz<=mij)
            update (2*nod,st,mij,poz,val);
        else
            update (2*nod+1,mij+1,dr,poz,val);
        aint[nod]=max (aint[2*nod],aint[2*nod+1]);
    }
}

void read ()
{
    int i,x;

    scanf ("%d%d",&n,&q);
    for (i=1; i<=n; ++i)
    {
        scanf ("%d",&x);
        update (1,1,n,i,x);
    }
}

void query (int nod,int st,int dr,int in,int sf)
{
    if (in<=st && dr<=sf)
        maxim=max (maxim,aint[nod]);
    else
    {
        int mij;

        mij=(st+dr)/2;
        if (in<=mij)
            query (2*nod,st,mij,in,sf);
        if (sf>mij)
            query (2*nod+1,mij+1,dr,in,sf);
    }
}

void solve ()
{
    int i,tip,x,y;

    for (i=1; i<=q; ++i)
    {
        scanf ("%d%d%d",&tip,&x,&y);
        if (tip==0)
        {
            maxim=0;
            query (1,1,n,x,y);
            printf ("%d\n",maxim);
        }
        else
            update (1,1,n,x,y);
    }
}

int main ()
{
    freopen ("arbint.in","r",stdin);
    freopen ("arbint.out","w",stdout);

    read ();
    solve ();

    return 0;
}