Cod sursa(job #2227989)

Utilizator mihai50000Mihai-Cristian Popescu mihai50000 Data 2 august 2018 13:34:23
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <bits/stdc++.h>

using namespace std;

#define IOS ios::sync_with_stdio(false), cin.tie(0);

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

const int N = 4e5 + 17;
const int INF = 0x3f3f3f3f;

int v[N];

void update(int st, int dr, int nod, int poz, int val)
{
	if(st == dr)
	{
		v[nod] = val;
		return;
	}
	int mij = (st + dr) / 2;
	if(poz <= mij) 
		update(st, mij, 2 * nod, poz, val);
	else 
		update(mij + 1, dr, 2 * nod + 1, poz, val);
	v[nod] = max(v[2 * nod], v[2 * nod + 1]);
}

int ans;

void query(int st, int dr, int nod, int a, int b)
{
	if(a <= st && dr <= b)
	{
		ans = max(ans, v[nod]);
		return;
	}
	int mij = (st + dr) / 2;
	if(a <= mij) 
		query(st, mij, 2 * nod, a, b);
	if(b > mij) 
		query(mij + 1, dr, 2 * nod + 1, a, b);
}

main()
{
	int n, q;
	in >> n >> q;
	for(int i = 1; i <= n; i++)
	{
		int x;
		in >> x;
		update(1, n, 1, i, x);
	}
	while(q--)
	{
		int task, a, b;
		in >> task >> a >> b;
		if(task)
			update(1, n, 1, a, b);
		else
		{
			ans = -INF;
			query(1, n, 1, a, b);
			out << ans << '\n';
		}
	}
}