Cod sursa(job #855344)

Utilizator deea101Andreea deea101 Data 14 ianuarie 2013 21:31:38
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
using namespace std;
ifstream f("arbint.in");
ofstream g("arbint.out");
int n,m,v[100001],arb[1<<18];
int maxim(int i, int a, int b, int st, int dr)
{
	if(a<=st && dr<=b) return arb[i];
	else if(st!=dr)
	{
		int mij,x=0,y=0; mij=(st+dr)/2;
		if(a<=mij) x=maxim(2*i,a,b,st,mij);
		if(b>mij) y=maxim(2*i+1,a,b,mij+1,dr);
		if(x>y) return x; 
			else return y;
	}
	else return 0;
}
void actualizare(int i, int nod, int val, int st, int dr)
{
	if(st==nod && nod==dr) arb[i]=val;
	int mij=(st+dr)/2;
	if(st!=dr && st<=nod && nod<=dr)
	{
		if(nod<=mij) actualizare(2*i,nod,val,st,mij);
		else actualizare(2*i+1,nod,val,mij+1,dr);
		
		if(arb[2*i]>arb[2*i+1]) arb[i]=arb[2*i];
		else arb[i]=arb[2*i+1];
		
	}
	
}
	
int main()
{
	f>>n>>m;
	int i,a,b,x;
	for(i=1;i<=n;i++)
	{
		f>>v[i];
		actualizare(1,i,v[i],1,n);
	}

	for(i=1;i<=m;i++)
	{
		f>>x;
		if(x==0)
		{
			f>>a>>b;
			g<<maxim(1,a,b,1,n);
			g<<'\n';
		}
		else 
		{
			f>>a>>b;
			actualizare(1,a,b,1,n);
		}
	}
}