Cod sursa(job #532149)

Utilizator feelshiftFeelshift feelshift Data 10 februarie 2011 21:39:10
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.55 kb
// http://infoarena.ro/problema/arbint
#include <fstream>
using namespace std;

#define maxSize 100001
#define leftChild 2*node
#define rightChild 2*node+1
#define begin first
#define end second

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

int lenght,operations;
int position,value,maxim;
pair<int,int> interval;
int tree[4*maxSize+66];

void update(int node,int left,int right);
void findMax(int node,int left,int right);

int main() {
	in >> lenght >> operations;

	for(position=1;position<=lenght;position++) {
		in >> value;
		
		update(1,1,lenght);
	}

	for(int i=1;i<=operations;i++) {
		bool type;

		in >> type;
		if(type) {
			in >> position >> value;
			update(1,1,lenght);
		}
		else {
			in >> interval.begin >> interval.end;
			maxim = 0;

			findMax(1,1,lenght);

			out << maxim << "\n";
		}
	}

	in.close();
	out.close();

	return (0);
}

void update(int node,int left,int right) {
	if(left == right) {
		tree[node] = value;

		return;
	}
	else {
		int middle = (left + right) / 2;

		if(position <= middle)
			update(leftChild,left,middle);
		else
			update(rightChild,middle+1,right);
	}

	tree[node] = max(tree[leftChild],tree[rightChild]);
}

void findMax(int node,int left,int right) {
	if(interval.begin <= left && interval.end >= right) {
		if(maxim < tree[node])
			maxim = tree[node];

		return;
	}
	else {
		int middle = (left + right) / 2;

		if(interval.begin <= middle)
			findMax(leftChild,left,middle);
		else
			findMax(rightChild,middle+1,right);
	}
}