programming-examples/java/Data_Structures/LookupCSV.java

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Java
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2019-11-15 12:59:38 +01:00
import edu.princeton.cs.introcs.In;
import edu.princeton.cs.introcs.StdIn;
import edu.princeton.cs.introcs.StdOut;
/*************************************************************************
* Compilation: javac LookupCSV.java
* Execution: java LookupCSV file.csv keyField valField
* Dependencies: ST.java In.java StdIn.java StdOut.java
* Data files: http://algs4.cs.princeton.edu/35applications/DJIA.csv
* http://algs4.cs.princeton.edu/35applications/UPC.csv
* http://algs4.cs.princeton.edu/35applications/amino.csv
* http://algs4.cs.princeton.edu/35applications/elements.csv
* http://algs4.cs.princeton.edu/35applications/ip.csv
* http://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
*
*
*************************************************************************/
public class LookupCSV {
public static void main(String[] args) {
int keyField = Integer.parseInt(args[1]);
int valField = Integer.parseInt(args[2]);
// symbol table
ST<String, String> st = new ST<String, String>();
// 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");
}
}
}