Cod sursa(job #470755)

Utilizator dushmiMihai-Alexandru Dusmanu dushmi Data 15 iulie 2010 14:09:21
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include<cstdio>
#define N 1<<17
int rasp,poz[N],val[4*N];
void first(int a,int b,int nod)
{
    if(a==b)
    {
        poz[a]=nod;
        return;
    }
    int mij=(a+b)/2;
    first(a,mij,2*nod);
    first(mij+1,b,2*nod+1);
}
int maxim(int x,int y)
{
    return x<y?y:x;
}
void modif(int nod)
{
    if(nod==0)
        return;
    val[nod]=maxim(val[2*nod],val[2*nod+1]);
    modif(nod/2);
}
void search(int nod,int st,int dr,int a,int b)
{
    if(b<st || a>dr)
        return;
    if(a<=st && b>=dr)
    {
        rasp=maxim(rasp,val[nod]);
        return;
    }
    if(st<dr)
    {
        int mij=(st+dr)/2;
        search(2*nod,st,mij,a,b);
        search(2*nod+1,mij+1,dr,a,b);
    }
}
void read()
{
    int n,m,x,a,b;
    scanf("%d%d",&n,&m);
    first(1,n,1);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&x);
        val[poz[i]]=x;
        modif(poz[i]/2);
    }
    for(int i=1;i<=m;i++)
    {
        scanf("%d",&x);
        if(x==1)
        {
            scanf("%d%d",&a,&b);
            val[poz[a]]=b;
            modif(poz[a]/2);
            continue;
        }
        scanf("%d%d",&a,&b);
        rasp=0;
        search(1,1,n,a,b);
        printf("%d\n",rasp);
    }
}
int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    read();
    return 0;
}