Cod sursa(job #833189)

Utilizator tudgal1001Profir Tudor tudgal1001 Data 11 decembrie 2012 23:58:15
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include<cstdio>
#include<algorithm>
#define NMax (1<<19)
using namespace std;

int arb[NMax],val,maxim;

void update (int nod, int st, int dr, int a, int b)
{
    if (a<=st && dr<=b)
    {
        arb[nod]=val;
        return;
    }
    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]);
    }
}

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

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);
            maxim=0;
            query(1,1,n,a,b);
            printf("%d\n",maxim);
        }
    }
    return 0;
}