Cod sursa(job #2897048)

Utilizator pielevladutPiele Vladut Stefan pielevladut Data 2 mai 2022 11:20:34
Problema Arbori de intervale Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <bits/stdc++.h>

#define int long long

using namespace std;

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

int n, m, v[100100];
int aint[400400];

void update(int nod, int st, int dr, int poz, int val)
{
    if(st == dr)
    {
        aint[nod] = val;
        return;
    }
    int mid = (st + dr) / 2;
    if(poz <= mid)
    {
        update(2 * nod, st, mid, poz, val);
    }
    else
    {
        update(2 * nod + 1, mid + 1, dr, poz, val);
    }
    aint[nod] = max(aint[2 * nod], aint[2 * nod + 1]);
}

int query(int nod, int st, int dr, int l, int r)
{
    if(st >= l && dr <= r)
    {
        return aint[nod];
    }
    if(st > r || dr < l || st > dr)
    {
        return 0;
    }
    int mid = (st + dr) / 2;
    return max(query(2 * nod, st, mid, l, r),
               query(2 * nod + 1, mid + 1, dr, l, r));
}

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