Below is the syntax highlighted version of TopM.java
from §2.4 Priority Queues.
/****************************************************************************** * Compilation: javac TopM.java * Execution: java TopM m < input.txt * Dependencies: MinPQ.java Transaction.java StdIn.java StdOut.java * Data files: https://algs4.cs.princeton.edu/24pq/tinyBatch.txt * * Given an integer m from the command line and an input stream where * each line contains a String and a long value, this MinPQ client * prints the m lines whose numbers are the highest. * * % java TopM 5 < tinyBatch.txt * Thompson 2/27/2000 4747.08 * vonNeumann 2/12/1994 4732.35 * vonNeumann 1/11/1999 4409.74 * Hoare 8/18/1992 4381.21 * vonNeumann 3/26/2002 4121.85 * ******************************************************************************/ /** * The {@code TopM} class provides a client that reads a sequence of * transactions from standard input and prints the <em>m</em> largest ones * to standard output. This implementation uses a {@link MinPQ} of size * at most <em>m</em> + 1 to identify the <em>M</em> largest transactions * and a {@link Stack} to output them in the proper order. * <p> * For additional documentation, see <a href="https://algs4.cs.princeton.edu/24pq">Section 2.4</a> * of <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin Wayne. * * @author Robert Sedgewick * @author Kevin Wayne */ public class TopM { // This class should not be instantiated. private TopM() { } /** * Reads a sequence of transactions from standard input; takes a * command-line integer m; prints to standard output the m largest * transactions in descending order. * * @param args the command-line arguments */ public static void main(String[] args) { int m = Integer.parseInt(args[0]); MinPQ<Transaction> pq = new MinPQ<Transaction>(m+1); while (StdIn.hasNextLine()) { // Create an entry from the next line and put on the PQ. String line = StdIn.readLine(); Transaction transaction = new Transaction(line); pq.insert(transaction); // remove minimum if m+1 entries on the PQ if (pq.size() > m) pq.delMin(); } // top m entries are on the PQ // print entries on PQ in reverse order Stack<Transaction> stack = new Stack<Transaction>(); for (Transaction transaction : pq) stack.push(transaction); for (Transaction transaction : stack) StdOut.println(transaction); } }