Cod sursa(job #544903)

Utilizator iconiKMircea Chirea iconiK Data 2 martie 2011 13:14:14
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <algorithm>
#include <fstream>
#include <vector>
using namespace std;

int a, b, val, o;
vector<int> v;

void update(int nod, int st, int dr);
void query(int nod, int st, int dr);

int main()
{
	ifstream in("arbint.in");
	ofstream out("arbint.out");
	
	int N, M;
	in >> N >> M;
	
	v.resize(5 * (N + 1), 0);

	for (int i = 1; i <= N; i++)
	{
		in >> val;
		
		a = i;
		update(1, 1, N);
	}

	for (int i = 1; i <= M; i++)
	{
		int t;
		in >> t >> a >> b;

		if (t == 0)
		{
			o = -1;

			query(1, 1, N);
			out << o << '\n';
		}
		else
		{
			val = b;

			update(1, 1, N);
		}
	}
}

void update(int nod, int st, int dr)
{
	if (st == dr)
	{
		v[nod] = val;
	}
	else
	{
		int mij = (st + dr) / 2;

		if (a <= mij)
			update(2 * nod, st, mij);
		else
			update(2 * nod + 1, mij + 1, dr);

		v[nod] = max(v[2 * nod], v[2 * nod + 1]);
	}
}

void query(int nod, int st, int dr)
{
	if ((a <= st) && (dr <= b))
	{
		o = max(o, v[nod]);
	}
	else
	{
		int mij = (st + dr) / 2;

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