Cod sursa(job #2175722)

Utilizator andreimuthMuth Andrei andreimuth Data 16 martie 2018 18:40:20
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.24 kb
#include <fstream>
using namespace std;
ifstream fin ("arbint.in");
ofstream fout ("arbint.out");
int n, m, i, x, y, op;
int arb[400002];

void update (int nod, int st, int dr, int a, int b, int val)
{
    if (dr < a || st > a)
        return ;
    if (st >= a && dr <= b)
        arb[nod] = val;
    else
    {
        int mij = (st + dr) / 2;
        update (2 * nod, st, mij, a, b, val);
        update (2 * nod + 1, mij + 1, dr, a, b, val);

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

int query (int nod, int st, int dr, int a, int b)
{
    if (dr < a || st > a)
        return 0;
    if (st >= a && dr <= b)
        return arb[nod];
    int mij = (st + dr) / 2;

    return max (query (2 * nod, st, mij, a, b), query (2 * nod + 1, mij + 1, dr, a, b));
}

int main()
{
    fin >> n >> m;
    for (i = 1; i <= n; i++)
    {
        fin >> x;
        update (1, 1, n, i, i, x);
    }

    for (i = 1; i <= m; i++)
    {
        fin >> op;
        if (op == 1)
        {
            fin >> x >> y;
            update (1, 1, n, x, x, y);
        }
        else
        {
            fin >> x >> y;
            fout << query (1, 1, n, x, y) << '\n';

        }
    }

    return 0;
}