Cod sursa(job #3250529)

Utilizator Laura139Anghel Laura Laura139 Data 21 octombrie 2024 17:07:08
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.56 kb
#include <fstream>
#include <cmath>

using namespace std;

ifstream cin("arbint.in");
ofstream cout("arbint.out");

int arbore[1048580], v[100001];
int m,n;

void initializare(int nod, int st, int dr)
{
    if(st==dr)
    {
        if(st<=n)
            arbore[nod]=v[st];
        else
            arbore[nod]=-1;
        return;
    }
    int med=(st+dr)/2;
    initializare(2*nod, st, med);
    initializare(2*nod+1, med+1, dr);
    arbore[nod]=max(arbore[2*nod], arbore[2*nod+1]);
}
void update(int st, int dr, int nod, int poz, int val_r)
{
    if(st==dr)
    {
        arbore[nod]=val_r;
        return;
    }
    int med=(st+dr)/2;
    if(poz<=med)
        update(st, med, 2*nod, poz, val_r);
    else
        update(med+1, dr, 2*nod+1, poz, val_r);
    arbore[nod]=max(arbore[2*nod], arbore[2*nod+1]);
}

int query(int st, int dr, int q_st, int q_dr, int nod)
{
    if(st>=q_st && dr<=q_dr)
        return arbore[nod];
    int med=(st+dr)/2, maxim=-1;
    if(q_st<=med)
        maxim=max(maxim, query(st, med, q_st, q_dr, 2*nod));
    if(q_dr>med)
        maxim=max(maxim, query(med+1, dr, q_st, q_dr, 2*nod+1));
    return maxim;
}

int main()
{
    int q;
    cin>>n>>q;
    m=pow(2, 1+floor(log2(n)+!(log2(n)==log2(n+1))));
    for(int i=1;i<=n;i++)
    {
        cin>>v[i];
    }
    initializare(1,1,m);
    for(int i=1;i<=q;i++)
    {
        int c,a,b;
        cin>>c>>a>>b;
        if(c==0)
            cout<<query(1, m, a, b, 1)<<'\n';
        if(c==1)
            update(1,m,1,a,b);
    }
    return 0;
}