Cod sursa(job #745121)

Utilizator fhandreiAndrei Hareza fhandrei Data 10 mai 2012 16:17:35
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.5 kb
//Include
#include <fstream>
#include <algorithm>
using namespace std;

//Definitii
#define leftSon (node<<1)
#define rightSon (node<<1)+1

//Constante
const int TREE_SIZE = (int)4e5+1;

//Functii
void update(int node, int left, int right);
void query(int node, int left, int right);

//Variabile
ifstream in("arbint.in");
ofstream out("arbint.out");

int elements, questions;
int tree[TREE_SIZE];
int type;
int position, value;
int leftRange, rightRange;

//Main
int main()
{
	in >> elements >> questions;
	
	for(position=1 ; position<=elements ; ++position)
		in >> value, update(1, 1, elements);
	
	while(questions--)
	{
		in >> type;
		if(type)
		{
			in >> position >> value;
			update(1, 1, elements);
		}
		else
		{
			in >> leftRange >> rightRange;
			value = 0;
			query(1, 1, elements);
			out << value << '\n';
		}
	}
	
	in.close();
	out.close();
	return 0;
}

void update(int node, int left, int right)
{
	if(left == right)
	{
		tree[node] = value;
		return ;
	}
	
	int mid = (left + right) >> 1;
	
	if(position <= mid)
		update(leftSon, left, mid);
	else
		update(rightSon, mid+1, right);
	
	tree[node] = max(tree[leftSon], tree[rightSon]);
}

void query(int node, int left, int right)
{
	if(leftRange <= left && right <= rightRange)
	{
		value = max(value, tree[node]);
		return ;
	}
	
	int mid = (left + right) >> 1;
	
	if(leftRange <= mid)
		query(leftSon, left, mid);
	if(mid < rightRange)
		query(rightSon, mid+1, right);
}