Cod sursa(job #2884038)

Utilizator pregoliStana Andrei pregoli Data 2 aprilie 2022 12:04:48
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.67 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;

struct AintNode {
    int maxi;
    AintNode() {}
    AintNode(int maxi) {
        this->maxi = maxi;
    }
} aint[NMAX * 4];

AintNode join(AintNode a, AintNode b) {
    return AintNode(max(a.maxi, b.maxi));
}

void Update(int nod, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        aint[nod] = AintNode(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] = join(aint[2 * nod], aint[2 * nod + 1]);
}

AintNode 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 {
        AintNode a, b;
        a = Query(2 * nod, st, mij, p1, mij);
        b = Query(2 * nod + 1, mij + 1, dr, mij + 1, p2);
        return join(a, b);
    }
}

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).maxi << newline;
    }

    return 0;
}