Cod sursa(job #2606584)

Utilizator michael_blazemihai mihai michael_blaze Data 28 aprilie 2020 01:52:49
Problema Arbori de intervale Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.54 kb
#include <cstdio>
#include <cmath>

#define max(a, b) ((a > b) ? (a) : (b))
#define MAX 100005

using namespace std;

long long arr[MAX], n, m;
long long arbore[3 * MAX + 1];

int max_intervals(int left, int right, int son) {
	if (arbore[son])
		return arbore[son];

	if (left == right) {
		arbore[son] = arr[left];
		return arr[left];
	}
	int mid = (left + right) / 2;

	arbore[son] = max(max_intervals(left, mid, 2 * son), 
		max_intervals(mid + 1, right, 2 * son + 1));
}

void update(int left, int right, int a, int b, int son) {
	if (left == right) {
		arbore[son] = b;
		arr[left] = b;
		return; 
	}
	int mid = (left + right) / 2;
	if (a <= mid)
		update(left, mid, a, b, 2 * son);
	else
		update(mid + 1, right, a, b, 2 * son + 1);
	arbore[son] = max(arbore[2 * son], arbore[2 * son + 1]);
}

int getMax(int left, int right,int a, int b, int son) {
	if (a <= left and right <= b)
		return arbore[son];
	int mid = (left + right) / 2;
	int Max = -1;
	if (a <= mid)
		Max = max(Max, getMax(left, mid, a, b, 2 * son));
	if (b > mid)
		Max = max(Max, getMax(mid + 1, right, a, b, 2 * son + 1));
	return Max;
}
int main() {
	freopen("arbint.in", "r", stdin);
	freopen("arbint.out", "w", stdout);

	scanf("%d%d", &n, &m);
	
	for (int i = 1;i <= n;i ++)
		scanf("%d", &arr[i]);

	max_intervals(1, n, 1);

	int operation, a, b;

	for (int i = 1;i <= m;i ++) {
		scanf("%d%d%d", &operation, &a, &b);

		if (operation)
			update(1, n, a, b, 1);
		else
			printf("%d\n",getMax(1, n, a, b, 1));
	}

	return 0;
}