Cod sursa(job #2404481)

Utilizator RaresLiscanLiscan Rares RaresLiscan Data 12 aprilie 2019 20:57:48
Problema Arbori de intervale Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <bits/stdc++.h>

using namespace std;

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

int T[200005], v[100005];

void actualizare(int nod, int st, int dr, int n, int val)
{
    if (dr < st) return;
    if (st == n && dr == n) T[nod] = val;
    else {
        int mij = (st + dr) / 2;
        if (n > mij) actualizare(2 * nod + 1, mij + 1, dr, n, val);
        if (n <= mij) actualizare(2 * nod, st, mij, n, val);
        T[nod] = max(T[2 * nod], T[2 * nod + 1]);
    }
}

int interogare (int nod, int st, int dr, int a, int b, int n)
{
    if (nod > 2 * n - 1 || st > dr) return 0;
    if (a <= st && b >= dr) return T[nod];
    else {
        int mij = (st + dr) / 2;
        int a1 = 0, a2 = 0;
        if (a <= mij)  a1 = interogare(2 * nod, st, mij, a, b, n);
        if (b > mij) a2 = interogare(2 * nod + 1, mij + 1, dr, a, b, n);
        return max(a1, a2);
    }
}

int main()
{
    int n, m;
    fin >> n >> m;
    int nod = 1;
    for (int i = 1; i <= n; i ++) {
        fin >> v[i];
        actualizare(nod, 1, n, i, v[i]);
    }
    int t, a, b;
    for (int i = 1; i <= m; i ++) {
        fin >> t >> a >> b;
        if (t == 0) fout << interogare(1, 1, n, a, b, n) << "\n";
        else actualizare(1, 1, n, a, b);
    }
    return 0;
}