Cod sursa(job #544863)

Utilizator iconiKMircea Chirea iconiK Data 2 martie 2011 11:59:56
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.23 kb
#include <algorithm>
#include <fstream>
#include <vector>
using namespace std;

int a, b, val, o;

void update(int nod, int st, int dr, vector<int> &v);
void query(int nod, int st, int dr, const vector<int> &v);

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

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

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

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

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

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

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

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

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

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

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