Cod sursa(job #277925)

Utilizator sigridMaria Stanciu sigrid Data 11 martie 2009 23:11:39
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include<stdio.h>
#define dim 100001
#define maxim(x,y) (x)>(y)?(x):(y)

long int v[3*dim],max,jum;

void update(long int nod, long int st, long int dr, long int poz, long int val)
{
 if(st==dr) v[nod]=val;
 
  else
    {
     jum=(st+dr)/2;
     
     if(poz<=jum) update(nod*2,st,jum,poz,val);
      
      else update(nod*2+1,jum+1,dr,poz,val);
      
     v[nod]=maxim(v[nod*2],v[nod*2+1]);
    }
}

void query(long int nod, long int st, long int dr, long int a, long int b)
{
 if( (a<=st) && (b>=dr) )
  {
   if(max<v[nod]) max=v[nod];
  }
  else
   {
    if( a <= ( ( st+dr ) / 2 ) ) query(nod*2,st,(st+dr)/2,a,b);
    
    if( b > ( ( st+dr ) / 2 ) ) query(nod*2+1,(st+dr)/2+1,dr,a,b);
   }
}

int main()
{
long int n,m,i,nr,x,y;

freopen("arbint.in","r",stdin);
freopen("arbint.out","w",stdout);

scanf("%ld %ld", &n, &m);

for(i=1;i<=n;i++)
 {
  scanf("%ld", &x);
  
  update(1,1,n,i,x);
 }
 
for(i=1;i<=m;i++)
 {
  scanf("%ld %ld %ld", &nr, &x, &y);
  
  if(nr==0)
   {
    max=0;
    
    query(1,1,n,x,y);
    
    printf("%ld\n",max);
   }
    else update(1,1,n,x,y);
 }

return 0;
}