Cod sursa(job #2902854)

Utilizator Teodor_AxinteAxinte Teodor-Ionut Teodor_Axinte Data 16 mai 2022 21:06:09
Problema Arbori de intervale Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.23 kb
#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

vector<int> arb(500010);
int n, m, x, y, a, b, op, val;

void update(int rad, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        arb[rad] = val;
        return;
    }
    int mij = (st + dr) / 2;
    if (poz <= mij)
        update(2 * rad, st, mij, poz, val);
    else
        update(2 * rad + 1, mij + 1, dr, poz, val);

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

int maxQuery(int rad, int st, int dr, int x, int y)
{
    if (x <= st && dr <= y)
        return arb[rad];

    int maxSt = 0, maxDr = 0;
    int mij = (st + dr) / 2;

    if (x < mij)
        maxSt = maxQuery(2 * rad, st, mij, x, y);
    if (mij < y)
        maxDr = maxQuery(2 * rad + 1, mij + 1, dr, x, y);

    return max(maxSt, maxDr);
}

int main()
{

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

    for (int i = 1; i <= m; i++)
    {
        fin >> op >> x >> y;
        if (op == 0)
            fout << maxQuery(1, 1, n, x, y)<<'\n';
        else
            update(1, 1, n, x, y);
    }
}