Cod sursa(job #1375138)

Utilizator valexVochescu Alexandru valex Data 5 martie 2015 12:21:11
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <cstdio>
#include <algorithm>
using namespace std;

int arb[1<<19];
int n,m,i,op,a,b,poz,x;

inline void actualizare(int nod, int st, int dr)
{
    int m;
    if (poz<=st&&poz>=dr)
    {
        arb[nod]=x;
        return;
    }
    m=(st+dr)/2;
    if (poz<=m) actualizare(2*nod,st,m);
    else actualizare(2*nod+1,m+1,dr);
    if (arb[nod*2]<arb[2*nod+1]) arb[nod]=arb[2*nod+1];
    else arb[nod]=arb[2*nod];
}

inline int interogare(int nod, int st, int dr)
{
    int m,x1,x2;
    x1=x2=0;
    if (a<=st&&b>=dr)
        return arb[nod];
    m=(st+dr)/2;
    if (a<=m) x1=interogare(nod*2,st,m);
    if (b>m) x2=interogare(nod*2+1,m+1,dr);
    if (x2>x1) x1=x2;
    return x1;
}


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