Cod sursa(job #2027503)

Utilizator PondorastiAlex Turcanu Pondorasti Data 26 septembrie 2017 10:35:54
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <algorithm>
using namespace std;
const int NMAX = 100000;
int aint[4 * NMAX + 5];
int n, m, x, i, a, b, q, ans;
void update(int node, int st, int dr, int poz, int x) {
    if(st == dr) {
        aint[node] = x;
        return;
    }
    int med = (st + dr) / 2;
    if(poz <= med)
        update(node * 2, st, med, poz, x);
    else
        update(node * 2 + 1, med + 1, dr, poz, x);
    aint[node] = max(aint[node * 2], aint[node * 2 + 1]);
}
void query(int node, int st, int dr) {
    if(a <= st && dr <= b) {
        ans = max(ans, aint[node]);
        return;
    }
    if(st == dr)
        return;
    int med = (st + dr) / 2;
    if(a <= med)
        query(node * 2, st, med);
    else if(b > med)
        query(node * 2 + 1, med + 1, dr);
    
}
int main() {
    ifstream cin("arbint.in");
    ofstream cout("arbint.out");
    cin >> n >> m;
    for(i = 1; i <= n; ++i) {
        cin >> x;
        update(1, 1, n, i, x);
    }
    for(i = 1; i <= m; ++i) {
        cin >> q >> a >> b;
        if(q == 0) {
            ans = 0;
            query(1, 1, n);
            cout << ans << "\n";
        } else {
            update(1, 1, n, a, b);
        }
    }
    return 0;
}