Cod sursa(job #2585941)

Utilizator tomitza.1604Sacuiu TomaAndrei tomitza.1604 Data 19 martie 2020 15:40:27
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <fstream>
using namespace std;

const int N = 1 << 18;
const int INF = 1 << 30;

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

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

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 interogare(int p, int st, int dr)///max [st,dr]^[a,b]
{
    if (a <= st && dr <= b)
    {
        return t[p];
    }
    int m = (st + dr) / 2, maxst = -INF, maxdr = -INF;
    if (a <= m)
    {
        maxst = interogare(2*p, st, m);
    }
    if (b > m)
    {
        maxdr = interogare(2*p + 1, m + 1, dr);
    }
    return max(maxst, maxdr);
}



int main()

{
    int n, m;
    in >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        in >> val;
        poz = i;
        actualizare(1, 1, n);
    }
    int tip;
    for (int i = 0; i < m; i++)
    {
        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;

}