edu.princeton.cs.algs4.LookupCSV Maven / Gradle / Ivy
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/******************************************************************************
* Compilation: javac LookupCSV.java
* Execution: java LookupCSV file.csv keyField valField
* Dependencies: ST.java In.java StdIn.java StdOut.java
* Data files: https://algs4.cs.princeton.edu/35applications/DJIA.csv
* https://algs4.cs.princeton.edu/35applications/UPC.csv
* https://algs4.cs.princeton.edu/35applications/amino.csv
* https://algs4.cs.princeton.edu/35applications/elements.csv
* https://algs4.cs.princeton.edu/35applications/ip.csv
* https://algs4.cs.princeton.edu/35applications/morse.csv
*
* Reads in a set of key-value pairs from a two-column CSV file
* specified on the command line; then, reads in keys from standard
* input and prints out corresponding values.
*
* % java LookupCSV amino.csv 0 3 % java LookupCSV ip.csv 0 1
* TTA www.google.com
* Leucine 216.239.41.99
* ABC
* Not found % java LookupCSV ip.csv 1 0
* TCT 216.239.41.99
* Serine www.google.com
*
* % java LookupCSV amino.csv 3 0 % java LookupCSV DJIA.csv 0 1
* Glycine 29-Oct-29
* GGG 252.38
* 20-Oct-87
* 1738.74
*
*
******************************************************************************/
package edu.princeton.cs.algs4;
/**
* The {@code LookupCSV} class provides a data-driven client for reading in a
* key-value pairs from a file; then, printing the values corresponding to the
* keys found on standard input. Both keys and values are strings.
* The fields to serve as the key and value are taken as command-line arguments.
*
* For additional documentation, see Section 3.5 of
* Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.
*
* @author Robert Sedgewick
* @author Kevin Wayne
*/
public class LookupCSV {
// Do not instantiate.
private LookupCSV() { }
public static void main(String[] args) {
int keyField = Integer.parseInt(args[1]);
int valField = Integer.parseInt(args[2]);
// symbol table
ST st = new ST();
// read in the data from csv file
In in = new In(args[0]);
while (in.hasNextLine()) {
String line = in.readLine();
String[] tokens = line.split(",");
String key = tokens[keyField];
String val = tokens[valField];
st.put(key, val);
}
while (!StdIn.isEmpty()) {
String s = StdIn.readString();
if (st.contains(s)) StdOut.println(st.get(s));
else StdOut.println("Not found");
}
}
}
/******************************************************************************
* Copyright 2002-2018, 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.
******************************************************************************/