Cod sursa(job #934256)

Utilizator gegeadDragos Gegea gegead Data 30 martie 2013 15:08:46
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include<fstream>
#include<cstdio>
#define inf 1000000001
using namespace std;
int a,b,poz,val,n;
int t[300001];

ifstream in("arbint.in");

inline int max(int a, int b)
{
    if(a>b)
        return a;
    return b;
}

void actualizare(int p, int st, int dr)
{
    if(st==dr)
    {
        t[p]=val;
        return;
    }
    int m=(st+dr)/2;
    if(poz<=m)
        actualizare(2*p,st,m);
    if(poz>m)
        actualizare(2*p+1,m+1,dr);
    t[p]=max(t[2*p],t[2*p+1]);
}




int interogare(int p, int st, int dr)
{
    if(a<=st&&dr<=b)
        return t[p];
    int m1=-inf,m2=-inf, m=(st+dr)/2;
    if(a<=m)
        m1=interogare(2*p,st,m);
    if(b>m)
        m2=interogare(2*p+1,m+1,dr);
    return max(m1,m2);
}





int main()
{
    //freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int m,i,x;
    bool p;
    in>>n>>m;
    for(i=1;i<=n;++i)
    {
        in>>x;
        poz=i;
        val=x;
        actualizare(1,1,n);
    }
    for(i=1;i<=m;++i)
    {
        in>>p;
        if(p==0)
        {
            in>>a>>b;
            printf("%d\n",interogare(1,1,n));
        }
        else
        {
            in>>poz>>val;
            actualizare(1,1,n);
        }
    }
    return 0;
}