Cod sursa(job #2920906)

Utilizator Alex_HossuHossu Alexandru Alex_Hossu Data 26 august 2022 15:24:03
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.19 kb
#include <fstream>

using namespace std;

#define MAXN 100005

int v[MAXN * 4];
void update(int n, int st, int dr, const int &pos, const int &val) {
  if (st == dr) {
    v[n] = val;
  } else {
    int mij = (st + dr) / 2;
    if (pos <= mij)
      update(2 * n, st, mij, pos, val);
    else
      update(2 * n + 1, mij + 1, dr, pos, val);
    v[n] = std::max(v[2 * n], v[2 * n + 1]);
  }
}

int query(int n, int st, int dr, int pos1, int pos2) {
  if (st == pos1 && dr == pos2) {
    return v[n];
  } else {
    int ans = -1;
    int mij = (st + dr) / 2;
    if (pos1 <= mij)
      ans = query(2 * n, st, mij, pos1, std::min(pos2, mij));
    if (pos2 >= mij + 1)
      ans = max(ans,
                query(2 * n + 1, mij + 1, dr, std::max(pos1, mij + 1), pos2));
    return ans;
  }
}

int main() {
  ifstream fin("arbint.in");
  ofstream fout("arbint.out");
  int n, m;
  int i, x;
  int op, a, b;

  fin >> n >> m;
  for (i = 1; i <= n; i++) {
    fin >> x;
    update(1, 1, n, i, x);
  }

  for (i = 0; i < m; i++) {
    fin >> op >> a >> b;
    if (op == 0) {
      fout << query(1, 1, n, a, b) << '\n';
    } else {
      update(1, 1, n, a, b);
    }
  }
}