Cod sursa(job #2301401)

Utilizator ElizaTElla Rose ElizaT Data 12 decembrie 2018 21:56:19
Problema Arbori de intervale Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
#include <bits/stdc++.h>

using namespace std;

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

int pom[400005];
int pos, val, ql, qr;

void build(int nod, int st, int dr)
{
    if (st == dr)
    {
        fin >> pom[nod];
        return;
    }
    int mid = (st + dr) / 2;
    build(2 * nod, st, mid);
    build(2 * nod + 1, mid + 1, dr);
    pom[nod] = max(pom[2 * nod], pom[2 * nod + 1]);
}
void update(int nod, int st, int dr)
{
    if (st == dr)
    {
        pom[nod] = val;
        return;
    }
    int md = (st + dr) / 2;
    if (pos <= md)
        update(2 * nod, st, md);
    else
        update(2 * nod + 1, md + 1, dr);
    pom[nod] = max(pom[2 * nod], pom[2 * nod + 1]);
}
int query(int nod, int st, int dr)
{
    if (ql <= st && dr <= qr)
        return pom[nod];
    int md = (st + dr) / 2, ans = -99999999;
    if (ql <= md)
        ans = max(ans, query (2 * nod, st, md));
    else
        ans = max(ans, query (2 * nod + 1, md + 1, dr));
    return ans;
}

int main()
{
    int n,m,a,b;
    bool ok;
    fin >> n >> m;
    build(1, 1, n);
    for (int i = 0;i < m;i++)
    {
        fin >> ok >> a >> b;
        if (ok == 1)
        {
            pos = a;
            val = b;
            update(1, 1, n);
        }
        else
        {
            ql = a;
            qr = b;
            fout << query(1, 1, n) << '\n';
        }
    }
    return 0;
}