Average.java 2.76 KB
/******************************************************************************
 *  Compilation:  javac Average.java
 *  Execution:    java Average < data.txt
 *  Dependencies: StdIn.java StdOut.java
 *  
 *  Reads in a sequence of real numbers, and computes their average.
 *
 *  % java Average
 *  10.0 5.0 6.0
 *  3.0 7.0 32.0
 *  [Ctrl-d]
 *  Average is 10.5
 *
 *  Note [Ctrl-d] signifies the end of file on Unix.
 *  On windows use [Ctrl-z].
 *
 ******************************************************************************/

package edu.princeton.cs.algs4;

/**
 *  The {@code Average} class provides a client for reading in a sequence
 *  of real numbers and printing out their average.
 *  <p>
 *  For additional documentation, see <a href="http://algs4.cs.princeton.edu/11model">Section 1.1</a> of
 *  <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin Wayne.
 *
 *  @author Robert Sedgewick
 *  @author Kevin Wayne
 */
public class Average { 

    // this class should not be instantiated
    private Average() { }

    /**
     * Reads in a sequence of real numbers from standard input and prints
     * out their average to standard output.
     *
     * @param args the command-line arguments
     */
    public static void main(String[] args) { 
        int count = 0;       // number input values
        double sum = 0.0;    // sum of input values

        // read data and compute statistics
        while (!StdIn.isEmpty()) {
            double value = StdIn.readDouble();
            sum += value;
            count++;
        }

        // compute the average
        double average = sum / count;

        // print results
        StdOut.println("Average is " + average);
    }
}

/******************************************************************************
 *  Copyright 2002-2016, Robert Sedgewick and Kevin Wayne.
 *
 *  This file is part of algs4.jar, which accompanies the textbook
 *
 *      Algorithms, 4th edition by Robert Sedgewick and Kevin Wayne,
 *      Addison-Wesley Professional, 2011, ISBN 0-321-57351-X.
 *      http://algs4.cs.princeton.edu
 *
 *
 *  algs4.jar is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  algs4.jar is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with algs4.jar.  If not, see http://www.gnu.org/licenses.
 ******************************************************************************/