Cod sursa(job #320163)

Utilizator TyberFMI Dogan Adrian Ioan Lucian Tyber Data 3 iunie 2009 19:47:28
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include<stdio.h>
#define nmax 100001
int n,m,arb[4*nmax+66],st,fn,val,pos,max;
int max1(int,int);
void update(int,int,int);
void query(int,int,int);
int main()
{
	int x,a,b;
	freopen("arbint.in","r",stdin);
	freopen("arbint.out","w",stdout);
	scanf("%d %d",&n,&m);
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&x);
		pos=i;
		val=x;
		update(1,1,n);
	}
	for(int i=1;i<=m;i++)
	{
		scanf("%d %d %d",&x,&a,&b);
		if(x==0)
		{
			max=-1;
			st=a;
			fn=b;
			query(1,1,n);
			printf("%d\n",max);
		}
		else
		{
			pos=a;
			val=b;
			update(1,1,n);
		}
	}
	return 0;
}
int max1(int a,int b)
{
	if(a>b)
		return a;
	else
		return b;
}
void update(int n,int l,int r)
{
	if(l==r)
	{
		arb[n]=val;
		return;
	}
	int d=(l+r)/2;
	if(pos<=d)
		update(2*n,l,d);
	else 
		update(2*n+1,d+1,r);
	arb[n]=max1(arb[2*n],arb[2*n+1]);
}
void query(int n,int l,int r)
{
	if(st<=l&&r<=fn)
	{
		if(max<arb[n])max=arb[n];
		return;
	}
	int d=(l+r)/2;
	if(st<=d)query(2*n,l,d);
	if(d<fn)query(2*n+1,d+1,r);
}