moving_average.java

/**
 * Created by xynophon on 15.1.12.
 */
import java.util.Random;
import java.util.Scanner;

public class moving_Average {
    //  O(n^2)
    public void solution(double[] weights, int num_ma){
        for(int cnt = 0; cnt <= weights.length-num_ma; cnt++){
            double weight_sum = 0.0;
            for(int i = cnt; i < cnt+num_ma; i++){
                weight_sum += weights[i];
            }
            System.out.println("avg : "+weight_sum/num_ma);
        }
    }
    
    //  O(n)
    public void solution_en(double[] weights, int num_ma){
        double sum = 0.0;
        for(int i = 0; i < num_ma-1; i++){
            sum += weights[i];
        }

        for(int i = num_ma-1; i < weights.length; i++){
            sum += weights[i];
            System.out.println("ma : "+ sum/num_ma);
            sum -= weights[i-num_ma+1];
        }
    }

    public static void main(String args[]){
        moving_Average ma = new moving_Average();

        System.out.print("how many items : ");
        Scanner sc = new Scanner(System.in);
        int how_many = sc.nextInt();
        double[] weights = new double[how_many];
        Random rnd = new Random();
        for(int count = 0; count <how_many; count++){
            weights[count] = rnd.nextDouble()*100;
        }

        System.out.print("moving avg : ");
        int num_ma = sc.nextInt();

        for(double weight:weights){
            System.out.println(weight + " ");
        }
        ma.solution_en(weights, num_ma);
        ma.solution(weights, num_ma);
    }
}