Cod sursa(job #1929481)

Utilizator PaulCbnCiobanu Paul PaulCbn Data 17 martie 2017 18:20:25
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include <iostream>
#include <cstdio>

#define NMAX 4*100005

using namespace std;

int N,M;
int ab[NMAX];

void update(int st,int dr,int val,int nod,int i)
{
    if(st==dr)
    {
        ab[nod]=val;
        return;
    }

    int mij = (st+dr)/2;

    if(i<=mij)
        update(st,mij,val,nod*2,i);
    else
        update(mij+1,dr,val,nod*2+1,i);

    ab[nod]=max(ab[nod*2],ab[nod*2+1]);

}

void query(int x,int y,int &maxim,int nod, int st,int dr)
{
    if(x<=st && dr<=y)
    {
        maxim = max(maxim,ab[nod]);
        return;
    }
    int mij = (st+dr)/2;

    if(x<=mij)
        query(x,y,maxim,nod*2,st,mij);
    if(y>mij)
        query(x,y,maxim,nod*2+1,mij+1,dr);


}

void rezolvare()
{
    scanf("%d%d",&N,&M);
    for(int i=1;i<=N;i++)
    {
        int a;
        scanf("%d",&a);
        update(1,N,a,1,i);
    }
    for(int i=1;i<=M;i++)
    {
        int q,a,b;
        scanf("%d%d%d",&q,&a,&b);
        if(q==0)
        {
            int maxim = 0;
            query(a,b,maxim,1,1,N);
            printf("%d\n",maxim);
        }
        else
        {
            update(1,N,b,1,a);
        }
    }
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    rezolvare();




    return 0;
}