Cod sursa(job #3152033)

Utilizator ungureanubogdan07Ungureanu Bogdan ungureanubogdan07 Data 23 septembrie 2023 16:34:50
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.54 kb
#include <fstream>
#include <vector>

using namespace std;

ifstream cin("arbint.in");
ofstream cout("arbint.out");

int n, q;
int v[100001], arbore[400001];

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

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

int query(int nod, int st, int dr, int stq, int drq)
{
    if(st >= stq && dr <= drq) {
        return arbore[nod];
    }
    int mij = (st + dr) / 2;

    if(mij >= drq) {
        return query(2 * nod, st, mij, stq, drq);
    }
    if(mij + 1 <= stq) {
        return query(2 * nod + 1, mij + 1, dr, stq, drq);
    }

    return max(query(2 * nod, st, mij, stq, drq), query(2 * nod + 1, mij + 1, dr, stq, drq));
}   

int main()
{
    cin >> n >> q;
    for(int i = 1; i <= n; ++i) {
        cin >> v[i];
    }
    build(1, 1, n);
    while(q--) {
        int op, x, y;
        cin >> op >> x >> y;
        if(op) {
            update(1, 1, n, x, y);
        }
        else {  
            cout << query(1, 1, n, x, y) << '\n';
        }
    }
    return 0;
}