Cod sursa(job #2130638)

Utilizator RazorBestPricop Razvan Marius RazorBest Data 13 februarie 2018 19:52:36
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <fstream>
using namespace std;

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

int t[200002];

void change(int nod, int st, int dr, int poz, int x)
{
    if (poz < st || poz > dr)
        return;
    if (st == dr)
    {
        t[nod] = x;
        return;
    }

    int mij = st + (dr - st) / 2;
    change(2 * nod, st, mij, poz, x);
    change(2 * nod + 1, mij + 1, dr, poz, x);
    t[nod] = max(t[2 * nod], t[2 * nod + 1]);
}

int max_int(int nod, int st, int dr, int a, int b)
{
    if (a > dr || b < st)
        return 0;
    if (a <= st && b >= dr)
        return t[nod];

    int mij = st + (dr - st) / 2;
    return max(max_int(2 * nod, st, mij, a, b), max_int(2 * nod + 1, mij + 1, dr, a, b));
}

int main()
{
    int x, op, a, b, m, n;

    fin >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        fin >> x;
        change(1, 1, n, i, x);
    }
    while (m--)
    {
        fin >> op >> a >> b;
        if (op == 0)
            fout << max_int(1, 1, n, a, b) << '\n';
        else
            change(1, 1, n, a, b);
    }
    return 0;
}