Cod sursa(job #158027)

Utilizator Sorin_IonutBYSorynyos Sorin_Ionut Data 13 martie 2008 13:38:47
Problema Range minimum query Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <iostream.h>
#include <fstream.h>

#define NMAX 100002
#define INF 0x3f3f3f3f
#define IN "rmq.in"
#define OUT "rmq.out"

ifstream fin(IN);
ofstream fout(OUT);

long int aint[NMAX*3];
long int n,m,mx;

void update(long int nod, long int st, long int dr, long int poz, long int val);
void query(long int nod, long int st, long int dr, long int a, long int b);
int min(int x,int y)
{
 if(x<y)
  return x;
return y;
}     

int main()
{
 long int i,x,y,k;

 fin>>n>>m;
  for (i=1;i<=n;i++)
  {
   fin>>x;
   update(1,1,n,i,x);
  }

  for (i=1;i<=m;i++)
  {
   fin>>x>>y;			
   mx=INF;
   query(1,1,n,x,y);
   
   fout<<mx<<endl;	 		    
  }
  
  fin.close();
  fout.close();
return 0;		
}

void update(long int nod, long int st, long int dr, long int poz, long int val)
{
if (st==dr) aint[nod]=val;
	else
	{
		long int mid=(st+dr)/2;

		if (poz<=mid) update(nod*2,st,mid,poz,val);
			else update(nod*2+1,mid+1,dr,poz,val);
		aint[nod]=min(aint[nod*2],aint[nod*2+1]);
	}

}

void query(long int nod, long int st, long int dr, long int a, long int b)
{
	if (a<=st&&dr<=b) mx=min(mx,aint[nod]);
		else
		{
			long int mid=(st+dr)/2;

			if (a<=mid) query(nod*2,st,mid,a,b);
			if (b>mid) query(nod*2+1,mid+1,dr,a,b);
		}
}