Cod sursa(job #3286730)

Utilizator robert_dumitruDumitru Robert Ionut robert_dumitru Data 14 martie 2025 16:24:19
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <bits/stdc++.h>
using namespace std;
//aproapeperm
ifstream fin("arbint.in");
ofstream fout("arbint.out");

int n, k, Q;
int aint[400005];

void Update(int p, int val)
{
    p += (n - 1);
    aint[p] = val;
    while (p > 1)
    {
        p /= 2;
        aint[p] = max(aint[2 * p], aint[2 * p + 1]);
    }
}
int Query(int k, int x, int y, int st, int dr)
{
    if (x == st && y == dr) return aint[k];
    int mij = (st + dr) / 2;

    if (y <= mij) return Query(2 * k, x, y, st, mij);
    if (x >= mij + 1) return Query(2 * k + 1, x, y, mij + 1, dr);
    return max(Query(2 * k, x, mij, st, mij), Query(2 * k + 1, mij + 1, y, mij + 1, dr));
}

int main()
{
    int op, A, B;
    fin >> k >> Q;
    for (n = 1; n < k; n *= 2)
        ;
    for (int i = 1; i <= k; i++)
        fin >> aint[n - 1 + i];
    for (int i = n - 1; i >= 1; i--)
        aint[i] = max(aint[2 * i], aint[2 * i + 1]);
    while (Q--)
    {
        fin >> op >> A >> B;
        if (op == 0) fout << Query(1, A, B, 1, n) << "\n";
        else Update(A, B);
    }
    return 0;
}