Cod sursa(job #2750652)

Utilizator Davla2Stancu Vlad Davla2 Data 12 mai 2021 17:57:42
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.33 kb
#include <fstream>

using namespace std;

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

const int N=1<<18;

int a,b,poz,val,t[N];

int interogare(int p, int st, int dr)
{
    if(a<=st && dr<=b)
    {
        return t[p];
    }
    int m=(st+dr)/2,maxst,maxdr;
    if(a<=m) //[a,b] intersecteaza prima jumatate
    {
        maxst=interogare(2*p, st, m);
    }
    else maxst=-1;
    if(m<b) //[a,b] intersecteaza a doua jumatate
    {
        maxdr=interogare(2*p+1, m+1, dr);
    }
    else maxdr=-1;
    return max(maxst, maxdr);
}

void actualizare(int p, int st, int dr)
{
    if(st==dr)
    {
        t[p]=val;
        return;
    }
    int m=(st+dr)/2;
    if(poz<=m)
    {
        actualizare(2*p, st, m);
    }
    else
    {
        actualizare(2*p+1, m+1, dr);
    }
    t[p]=max(t[2*p], t[2*p+1]);
}

int main()
{
    int n,m;
    in>>n>>m;
    for(int i=1; i<=n; i++)
    {
        in>>val;
        poz=i;
        actualizare(1, 1, n);
    }
    for(int i=0; i<m; i++)
    {
        int tip;
        in>>tip;
        if(tip==0)
        {
            in>>a>>b;
            out<<interogare(1, 1, n)<<"\n";
        }
        else
        {
            in>>poz>>val;
            actualizare(1, 1, n);
        }
    }
    in.close();
    out.close();
    return 0;
}