Cod sursa(job #833184)

Utilizator tudgal1001Profir Tudor tudgal1001 Data 11 decembrie 2012 23:51:34
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include<cstdio>
#include<algorithm>
#define NMax (1<<18)
using namespace std;

int arb[NMax],val;

void update (int nod, int st, int dr, int a, int b)
{
    if (a<=st && dr<=b)
        arb[nod]=val;
    else
    {
        int mij=(st+dr)/2;
        if (a<=mij)
            update(2*nod,st,mij,a,b);
        if (b>mij)
            update(2*nod+1,mij+1,dr,a,b);
        arb[nod]=max(arb[2*nod],arb[2*nod+1]);
    }
}

int query (int nod, int st, int dr, int a, int b)
{
    if (a<=st && dr<=b)
        return arb[nod];
    else
    {
        int x=0,y=0,mij=(st+dr)/2;
        if (a<=mij)
            x=query(2*nod,st,mij,a,b);
        if (b>mij)
            y=query(2*nod+1,mij+1,dr,a,b);
        return max(x,y);
    }
}

int main ()
{
    int n,m,i,tip,poz,a,b;
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1; i<=n; i++)
    {
        scanf("%d",&val);
        update(1,1,n,i,i);
    }
    for (i=1; i<=m; i++)
    {
        scanf("%d",&tip);
        if (tip)
        {
            scanf("%d%d",&poz,&val);
            update(1,1,n,poz,poz);
        }
        else
        {
            scanf("%d%d",&a,&b);
            printf("%d\n",query(1,1,n,a,b));
        }
    }
    return 0;
}