Cod sursa(job #331813)

Utilizator IoannaPandele Ioana Ioanna Data 15 iulie 2009 13:23:45
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include<fstream>
#define nmax 300010
long n,a,b,o,m;
long t[nmax];

using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

long max(long a,long b)
{
if (a>b)
    return a;
return b;
}

void update(long k,long st,long dr,long a,long b)
{
long mij;
if (st==dr)
   {
    t[k]=b;
    return;
   }
mij=(st+dr)/2;
if (a<=mij)
    update(2*k,st,mij,a,b);
else update(2*k+1,mij+1,dr,a,b);
t[k]=max(t[2*k],t[2*k+1]);
}

void read()
{
f>>n>>m;
long i;
for (i=1;i<=n;i++)
    {
     f>>a;
     update(1,1,n,i,a);
     }
}


long interv(long k,long st,long dr,long a,long b)
{
long mij,fs=0,fd=0;
if (a<=st && b>=dr)
    return t[k];
mij=(st+dr)/2;
if (a<=mij)
    fs=interv(2*k,st,mij,a,b);
if (b>mij)
    fd=interv(2*k+1,mij+1,dr,a,b);
return max(fs,fd);
}

int main()
{
read();
long i;
for (i=1;i<=m;i++)
     {
      f>>o>>a>>b;
      if (!o)
         {
          g<<interv(1,1,n,a,b)<<"\n";
         }
      else {
            update(1,1,n,a,b);
           }
     }
return 0;
}