Cod sursa(job #1016332)

Utilizator Cosmin1490Balan Radu Cosmin Cosmin1490 Data 26 octombrie 2013 07:42:58
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.7 kb
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <iterator>
#include <assert.h>
using namespace std;

const string file = "rmq";

const string infile = file + ".in";
const string outfile = file + ".out";

const int INF = 0x3f3f3f3f;

vector<int> A;
int N, M;
vector<int> lg;


vector<vector<int>> RMQ;

void initRmq()
{
	lg[2] = 1;
	for(int i = 3; i <= N; i++)
	{
		lg[i] = lg[i/2] + 1;
	}

	RMQ.resize(lg[N] + 1);

	RMQ[0].resize(N);

	for(int i = 0; i < N; i++)
	{
		RMQ[0][i] = A[i];
	}

	for(int i = 1; i<= lg[N]; i++)
	{
		RMQ[i].resize(N - (1 << i) + 1);
		for(int j = 0; j + (1 << i) <= N; j++)
		{
			RMQ[i][j] = min(RMQ[i-1][j], RMQ[i-1][j + (1 << (i -1))]);
		}
	}

}

int query(int x, int y)
{
	if(x > y)
		swap(x, y);

	x--;
	y--;

	int d = y - x + 1;
	int l = lg[d];
	int diff = d - (1 << l);

	return min(RMQ[l][x], RMQ[l][x+diff]);


}

int main()
{
	fstream fin(infile.c_str(), ios::in);
	fstream fout(outfile.c_str(), ios::out);

	fin >> N >> M;

	A.resize(N);
	lg.resize(N + 1);

	for(int i = 0; i < N; i++)
	{
		fin >> A[i];
	}

	initRmq();

	for(int i = 0; i < M; i++)
	{
		int x, y;
		fin >> x >> y;
		fout << query(x, y) << "\n";
	}
	

	
	fout.close();
	fin.close();
}