Cod sursa(job #2902485)

Utilizator BojneaguBojneagu David-Alexandru Bojneagu Data 16 mai 2022 15:20:39
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.32 kb
#include <iostream>
#include <fstream>
using namespace std;

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


#define MAXN 500000
int arbint[MAXN];

int query(int nod, int left, int right, int a, int b) {

    if (left >= a && b >= right)
        return arbint[nod];

    int mid = (left + right) / 2, v1 = 0, v2 = 0;

    if (a <= mid)
        v1 = query(nod * 2, left, mid, a, b);

    if (b > mid)
        v2 = query(nod * 2 + 1, mid + 1, right, a, b);

    return max(v1, v2);
}

void update(int nod, int left, int right, int poz, int val) {
    if (left == right) {

        arbint[nod] = val;
        return;
    }
    int mid = (left + right) / 2;

    if (poz <= mid)

        update(nod * 2, left, mid, poz, val);

    else

        update(nod * 2 + 1, mid + 1, right, poz, val);

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



int main() {
    int n, m, nr1, nr2, op;

    fin >> n >> m;

    for (int i = 1; i <= n; ++i) {
        fin >> nr1;
        update(1, 1, n, i, nr1);
    }

    for (int i = 0; i < m; ++i) {

        fin >> op >> nr1 >> nr2;
        if (op == 0)
            fout << query(1, 1, n, nr1, nr2) << "\n";
        else
            update(1, 1, n, nr1, nr2);
    }

    fin.close();
    fout.close();
    return 0;

}