Cod sursa(job #2777284)

Utilizator pregoliStana Andrei pregoli Data 22 septembrie 2021 19:45:04
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <bits/stdc++.h>
#define newline '\n'
using namespace std;
const string fname("arbint");
ifstream fin(fname + ".in");
ofstream fout(fname + ".out");
///************************

const int NMAX = 1e5 + 5;
int n, m;
int aint[NMAX * 4];

void Update(int nod, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        aint[nod] = val;
        return;
    }

    int mij = st + (dr - st) / 2;
    if (poz <= mij)
        Update(nod * 2, st, mij, poz, val);
    else
        Update(nod * 2 + 1, mij + 1, dr, poz, val);
    aint[nod] = max(aint[2 * nod], aint[2 * nod + 1]);
}

int Query(int nod, int st, int dr, int p1, int p2)
{
    if (p1 == st && p2 == dr)
    {
        return aint[nod];
    }

    int mij = st + (dr - st) / 2;
    if (p2 <= mij)
        return Query(2 * nod, st, mij, p1, p2);
    else if (p1 > mij)
        return Query(2 * nod + 1, mij + 1, dr, p1, p2);
    else
        return max(Query(2 * nod, st, mij, p1, mij), Query(2 * nod + 1, mij + 1, dr, mij + 1, p2));
}

int main()
{
    fin >> n >> m;
    for (int x, i = 1; i <= n; i++)
    {
        fin >> x;
        Update(1, 1, n, i, x);
    }
    int a, b;
    bool c;
    while (m--)
    {
        fin >> c >> a >> b;
        if (c == true)
            Update(1, 1, n, a, b);
        else
            fout << Query(1, 1, n, a, b) << newline;
    }

    return 0;
}