Cod sursa(job #2709771)

Utilizator gasparrobert95Gaspar Robert Andrei gasparrobert95 Data 21 februarie 2021 11:15:34
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
#include <bits/stdc++.h>
#define ll long long
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n, q, v[100005], aint[400005];

void build(int nod, int a, int b) {
    if (a == b) {
        aint[nod] = v[a];
        return;
    }
    int mij = (a + b) / 2;
    build(nod * 2, a, mij);
    build(nod * 2 + 1, mij + 1, b);
    aint[nod] = max(aint[nod * 2], aint[nod * 2 + 1]);
    return;
}

int query(int nod, int st, int dr, int a, int b) {
    if (st >= a && dr <= b)
        return aint[nod];
    int mij = (st + dr) / 2, rez = 0;
    if (mij >= a)
        rez = max(rez, query(nod * 2, st, mij, a, b));
    if (mij + 1 <= b)
        rez = max(rez, query(nod * 2 + 1, mij + 1, dr, a, b));
    return rez;
}

void upd(int nod, int st, int dr, int pos, int val) {
    if (st == dr) {
        aint[nod] = val;
        return;
    }
    int mij = (st + dr) / 2;
    if (mij >= pos)
        upd(nod * 2, st, mij, pos, val);
    else
        upd(nod * 2 + 1, mij + 1, dr, pos, val);
    aint[nod] = max(aint[nod * 2], aint[nod * 2 + 1]);
    return;
}

int main() {
    fin >> n >> q;
    for (int i = 1; i <= n; ++i)
        fin >> v[i];
    build(1, 1, n);
    while (q--) {
        int c, a, b;
        fin >> c >> a >> b;
        if (c == 0)
            fout << query(1, 1, n, a, b) << "\n";
        else
            upd(1, 1, n, a, b);
    }
    return 0;
}