Cod sursa(job #644473)

Utilizator the@EyE@Postavaru Stefan the@EyE@ Data 6 decembrie 2011 19:54:38
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include<stdio.h>
#define max(a,b) a>b?a:b

int tree[99999999],n,q;

void update(int nod,int st,int dr,int poz,int val)
{
	if(st==poz&&dr==poz)tree[nod]=val;
	else
	{
		int m=(st+dr)>>1;
		if(poz<=m)update((nod<<1),st,m,poz,val);
		else update((nod<<1)+1,m+1,dr,poz,val);
		tree[nod]=max(tree[(nod<<1)],tree[(nod<<1)+1]);
	}
}

int getMax(int nod,int st,int dr,int a,int b)
{
	if(a<=st&&dr<=b)return tree[nod];
	else
	{
		int l=0,r=0;
		int m=(st+dr)>>1;
		if(a<=m)l=getMax((nod<<1),st,m,a,b);
		if(b>m)r=getMax((nod<<1)+1,m+1,dr,a,b);
		return max(l,r);
	}
}

int main()
{
	freopen("arbint.in","r",stdin);
	freopen("arbint.out","w",stdout);
	scanf("%d %d\n",&n,&q);
	for(int i=1;i<=n;i++)
	{
		int x;
		scanf("%d",&x);
		update(1,1,n,i,x);
	}
	scanf("\n");
	for(int i=0;i<q;i++)
	{
		int cmd,a,b;
		scanf("%d %d %d\n",&cmd,&a,&b);
		if(cmd==0)printf("%d\n",getMax(1,1,n,a,b));
		else update(1,1,n,a,b);		
	}
	
}