Cod sursa(job #2982926)

Utilizator hutanuHutanu Andrei hutanu Data 21 februarie 2023 09:57:57
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.52 kb
#include <fstream>

using namespace std;

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

int n, m, v[100005];
int arb[400005];

void build(int nod, int st, int dr)
{
    if(st == dr)
    {
        arb[nod] = v[st];
        return;
    }
    int mij = (st + dr) / 2;
    build(nod * 2, st, mij);
    build(nod * 2 + 1, mij + 1, dr);
    arb[nod] = max(arb[nod * 2], arb[nod * 2 + 1]);
}

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

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

int main()
{
    int i, tip, poz, val, L, R;
    fin >> n >> m;
    for(i = 1; i <= n; i++)
        fin >> v[i];
    build(1, 1, n);
    for(i = 1; i <= m; i++)
    {
        fin >> tip;
        if(tip == 1)
        {
            fin >> poz >> val;
            update(1, 1, n, poz, val);
        }
        else
        {
            fin >> L >> R;
            fout << query(1, 1, n, L, R) << '\n';
        }
    }
    return 0;
}