Cod sursa(job #2808933)

Utilizator moise_alexandruMoise Alexandru moise_alexandru Data 25 noiembrie 2021 18:03:16
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");
const int maxn = 100005;
int aint[maxn * 4];

void update(int nod, int x, int y, int poz, int val)
{
    if(poz < x || poz > y)
        return;
    if(x == y)
    {
        aint[nod] = val;
        return;
    }
    int mij = (x + y) / 2;
    update(nod * 2, x, mij, poz, val);
    update(nod * 2 + 1, mij + 1, y, poz, val);
    aint[nod] = max(aint[nod * 2], aint[nod * 2 + 1]);
}

int query(int nod, int st, int dr, int x, int y)
{
    if(y < st || x > dr)
        return 0;
    if(x <= st && dr <= y)
        return aint[nod];
    int mij = (st + dr) / 2;
    int stanga = query(nod * 2, st, mij, x, y);
    int dreapta = query(nod * 2 + 1, mij + 1, dr, x, y);
    return max(stanga, dreapta);
}

int main()
{
    int n, m;
    in >> n >> m;
    for(int i = 1; i <= n; i++)
    {
        int x;
        in >> x;
        update(1, 1, n, i, x);
    }
    for(int i = 1; i <= m; i++)
    {
        int op, a, b;
        in >> op >> a >> b;
        //cerr << op << " " << a << " " << b << "\n";
        if(op == 1)
            update(1, 1, n, a, b);
        else
            out << query(1, 1, n, a, b) << "\n";
    }
    return 0;
}