Cod sursa(job #2187246)

Utilizator razvanboabesrazvan boabes razvanboabes Data 26 martie 2018 12:29:05
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.37 kb
#include <fstream>

using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");
int v[100005];
int sol;
int aint[500005];
void build(int nod,int st,int dr)
{
    if(st==dr)
         aint[nod]=v[st];
  else
  {
      int med;
      med=(st+dr)/2;
      build(2*nod,st,med);
      build(2*nod+1,med+1,dr);
      aint[nod]=max(aint[2*nod],aint[2*nod+1]);
  }
}
void update(int nod,int st,int dr,int pozv,int val)
{
    if(st==dr)
         aint[nod]=val;
  else
  {
      int med;
      med=(st+dr)/2;
      if(pozv<=med)
        update(2*nod,st,med,pozv,val);
     if(pozv>med)
        update(2*nod+1,med+1,dr,pozv,val);
      aint[nod]=max(aint[2*nod],aint[2*nod+1]);
  }
}
void query(int nod,int st, int dr,int a,int b)
{
    if(a<=st and dr<=b)
          sol=max(sol,aint[nod]);
    else
    {
        int med;
        med=(st+dr)/2;
        if(a<=med)
          query(2*nod,st,med,a,b);
        if(b>med)
          query(2*nod+1,med+1,dr,a,b);
    }
}
int main()
{
    int i,n,m,a,b;
    bool c;
    in>>n>>m;
    for(i=1;i<=n;i++)
        in>>v[i];
    build(1,1,n);
    for(i=1;i<=m;i++)
    {
        in>>c>>a>>b;
        if(c==1)
            update(1,1,n,a,b);
          else if(c==0)
          {
              sol=0;
             query(1,1,n,a,b);
             out<<sol<<'\n';
          }
    }
    return 0;
}