Cod sursa(job #2032146)

Utilizator stefan_creastaStefan Creasta stefan_creasta Data 4 octombrie 2017 17:10:02
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include <cstdio>
#include <algorithm>
using namespace std;
const int NMAX = 100000;
int v[NMAX * 2 + 5];
void update(int nod, int poz, int val, int st, int dr)
{
  if(st == dr) {
    v[nod] = val;
    return ;
  }
  int mij = (st + dr) / 2;
  if(poz <= mij) {
    update(nod * 2, poz, val, st, mij);
  }
  else {
    update(nod * 2 + 1, poz, val, mij + 1, dr);
  }
  v[nod] = max(v[nod * 2], v[nod * 2 + 1]);
}
int query(int nod, int a, int b, int st, int dr)
{
  if(a <= st && dr <= b) {
    return v[nod];
  }
  int sol1 = 0, sol2 = 0;
  int mij = (st + dr) / 2;
  if(a <= mij) {
    sol1 = query(nod * 2, a, b, st, mij);
  }
  if(mij < b) {
    sol2 = query(nod * 2 + 1, a, b, mij + 1, dr);
  }
  return max(sol1, sol2);
}

int main()
{
  int n, m;
  freopen("arbint.in", "r", stdin);
  freopen("arbint.out", "w", stdout);
  scanf("%d%d", &n, &m);
  for(int i = 1; i <= n; ++i) {
    int val;
    scanf("%d", &val);
    update(1, i, val, 1, n);
  }
  for(int q = 0; q < m; ++q) {
    int t, a, b;
    scanf("%d%d%d", &t, &a, &b);
    if(t == 1) {
      update(1, a, b, 1, n);
    }
    else {
      printf("%d\n", query(1, a, b, 1, n));
    }
  }
  return 0;
}