Cod sursa(job #1591488)

Utilizator andrei_diaconuAndrei Diaconu andrei_diaconu Data 6 februarie 2016 12:39:38
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <fstream>

#define NMax 100010

using namespace std;

ifstream f("rmq.in");
ofstream g("rmq.out");

int n, queries, elem[NMax], lg[NMax], RMQ[17][NMax];

int getMin(int a, int b)
{
	if (a < b)
		return a;
	return b;
}

void preprocess()
{
	for (int i = 2; i <= n; i++)
		lg[i] = lg[i / 2] + 1;

	for (int i = 1; i <= lg[n]; i++) {
		for (int j = 1; j <= n - (1 << i) + 1; j++) {
			if (elem[RMQ[i - 1][j]] < elem[RMQ[i - 1][j + (1 << (i - 1))]])
				RMQ[i][j] = RMQ[i - 1][j];
			else
				RMQ[i][j] = RMQ[i - 1][j + (1 << (i - 1))];
		}
	}
}

int main()
{
	f >> n >> queries;
	for (int i = 1; i <= n; i++) {
		f >> elem[i];
		RMQ[0][i] = i;
	}

	preprocess();

	int a, b;
	for (int i = 1; i <= queries; i++) {
		f >> a >> b;

		int line = lg[b - a + 1];

		if (elem[RMQ[line][a]] < elem[RMQ[line][b - (1 << line) + 1]])
			g << elem[RMQ[line][a]] << "\n";
		else
			g << elem[RMQ[line][b - (1 << line) + 1]] << "\n";
	}
}