Cod sursa(job #165406)

Utilizator mihai0110Bivol Mihai mihai0110 Data 25 martie 2008 22:23:09
Problema Arbori de intervale Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.46 kb
#include <stdio.h>
#include <fstream.h>
 


#define in "arbint.in"
#define out "arbint.out"
#define dim 1001

int N, M;
int MaxArb[4*dim+66];
int start, finish, Val, Pos, maxim;

inline int Maxim(int a, int b) {
       if ( a > b ) return a;
       return b;
}
 
void Update(int,int,int);
void Query(int,int,int);

int main()
{
	int X, A, B,i;
	freopen(in,"r",stdin);
	freopen(out,"w",stdout);

	scanf("%d%d", &N, &M);
	for ( i = 1; i <= N; i++ )
	{
		scanf("%d", &X);
		Pos = i, Val = X;
		Update(1,1,N);
	}

	for ( i = 1; i <= M; i++ )
	{
		scanf("%d%d%d", &X, &A, &B);
		if ( X == 0 )
		{
			 maxim = -1;
			 start = A, finish = B;
			 Query(1,1,N);

			 printf("%d\n", maxim);
		}
		else
		{
			Pos = A, Val = B;
			Update(1,1,N);
		}
	}
	return 0;
}

void Update(int nod, int left, int right)
{
     if ( left == right )
     {
          MaxArb[nod] = Val;
          return;
     }
     
     int div = (left+right)/2;
     if ( Pos <= div ) Update(2*nod,left,div);
     else              Update(2*nod+1,div+1,right);
     
     MaxArb[nod] = Maxim( MaxArb[2*nod], MaxArb[2*nod+1] );
}

void Query(int nod, int left, int right)
{
     if ( start <= left && right <= finish )
     {
          if ( maxim < MaxArb[nod] ) maxim = MaxArb[nod];
          return;
     }
     
     int div = (left+right)/2;
     if ( start <= div ) Query(2*nod,left,div);
     if ( div < finish ) Query(2*nod+1,div+1,right);
}