BlakesHomework.java

package io.hadyn.politics;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import java.util.function.Supplier;
import java.util.stream.Collectors;

/**
 * @author Hadyn Fitzgerald
 */
public class Runner {
  public static void main(String... args) {
    try(BufferedReader reader = Files.newBufferedReader(Paths.get("data.txt"))) {

      // Chomp the header.
      chomp(reader, 6);

      List<DataEntry> entries = new ArrayList<>();
      while(reader.ready()) {
        entries.add(readEntry(reader));
      }

      // Remove any entries that are not for clinton or sanders since we will not be analyzing
      // their data.
      entries.removeIf(entry -> !entry.getCandidateName().equals("Clinton") &&
              !entry.getCandidateName().equals("Sanders"));

      assert(entries.size() / 2 == 1683);

      Set<String> countiesAndPrecincts = entries.stream()
              .map(entry -> entry.getCountyName() + "+" + entry.getPrecinctName())
              .collect(Collectors.toSet());

      List<Result> results = new ArrayList<>();
      for(String countyAndPrecinct : countiesAndPrecincts) {
        String county = countyAndPrecinct.substring(0, countyAndPrecinct.indexOf('+'));
        String precinct = countyAndPrecinct.substring(countyAndPrecinct.indexOf('+') + 1);

        List<DataEntry> precinctEntries = entries.stream()
                .filter(entry -> entry.getCountyName().equals(county) &&
                        entry.getPrecinctName().equals(precinct))
                .collect(Collectors.toList());

        if(precinctEntries.size() > 2) {
          throw new IllegalStateException("Expected only two results.");
        }

        Result precinctResult = new Result(county, precinct);
        for(DataEntry entry : precinctEntries) {
          if(entry.getCandidateName().equals("Clinton")) {
            precinctResult.setClintonEntry(entry);
          } else {
            precinctResult.setSandersEntry(entry);
          }
        }

        results.add(precinctResult);
      }

      Supplier<TreeSet<Result>> supplier = () ->
              new TreeSet<>((first, second) -> Double.compare(first.getEquivalent(),
                      second.getEquivalent()));

      // Create a new heap of the results we can then iterate over to find the best results. This
      // set will be in ascending order.
      TreeSet<Result> sortedResults = results.stream()
              .collect(Collectors.toCollection(supplier));

      Result bestSandersResult = null;
      Result bestClintonResult = null;

      // Search for the best precinct result for each canidate.
      Result result;
      while(bestSandersResult == null || bestClintonResult == null) {
        result = sortedResults.pollLast();

        if(result.isSandersPrecinct()) {
          if(bestSandersResult == null) {
            bestSandersResult = result;
          }
        } else {
          if(bestClintonResult == null) {
            bestClintonResult = result;
          }
        }
      }
      
      try(BufferedWriter writer = Files.newBufferedWriter(Paths.get("bestprecincts.txt"))) {
        writer.write(bestSandersResult.toString());
        writer.newLine();

        writer.write(bestClintonResult.toString());
        writer.newLine();

        writer.flush();
      } catch (IOException ex) {
        System.out.println("Failed to write to output file.");
      }
    } catch (IOException e) {
      System.out.println("Failed to open the data file.");
    }
  }

  private static void chomp(BufferedReader reader, int lineCount) throws IOException {
    if(lineCount < 1) {
      throw new IllegalArgumentException("Line count cannot be less than one.");
    }

    while(lineCount-- > 0) {
      reader.readLine();
    }
  }

  private static DataEntry readEntry(BufferedReader reader) throws IOException {
    String countyName = reader.readLine();
    String precictName = reader.readLine();
    String canidateName = reader.readLine();
    int delegatesWon = Integer.parseInt(reader.readLine());
    int delegatesToElect = Integer.parseInt(reader.readLine());
    double equivalent = Double.parseDouble(reader.readLine());
    return new DataEntry(countyName, precictName, canidateName,
            delegatesWon, delegatesToElect, equivalent);
  }

  private static class DataEntry {
    private String countyName;
    private String precinctName;
    private String candidateName;
    private int delegatesWon;
    private int delegatesToElect;
    private double equivalent;

    DataEntry(String countyName, String precinctName, String candidateName,
              int delegatesWon, int delegatesToElect, double equivalent) {
      this.countyName = countyName;
      this.precinctName = precinctName;
      this.candidateName = candidateName;
      this.delegatesWon = delegatesWon;
      this.delegatesToElect = delegatesToElect;
      this.equivalent = equivalent;
    }

    public String getCountyName() {
      return countyName;
    }

    public String getPrecinctName() {
      return precinctName;
    }

    public String getCandidateName() {
      return candidateName;
    }

    public int getDelegatesWon() {
      return delegatesWon;
    }

    public int getDelegatesToElect() {
      return delegatesToElect;
    }

    public double getEquivalent() {
      return equivalent;
    }
  }

  private static class Result {
    String precinct;
    String county;
    DataEntry sandersEntry;
    DataEntry clintonEntry;

    Result(String county, String precinct) {
      this.precinct = precinct;
      this.county = county;
    }

    void setSandersEntry(DataEntry entry) {
      sandersEntry = entry;
    }

    void setClintonEntry(DataEntry entry) {
      clintonEntry = entry;
    }

    double getSandersEquivalent() {
      return sandersEntry.getEquivalent();
    }

    double getClintonEquivalent() {
      return clintonEntry.getEquivalent();
    }

    double getEquivalent() {
      return Math.max(getSandersEquivalent() - getClintonEquivalent(),
              getClintonEquivalent() - getSandersEquivalent());
    }

    boolean isSandersPrecinct() {
      return getSandersEquivalent() > getClintonEquivalent();
    }

    @Override
    public String toString() {
      StringBuilder builder = new StringBuilder();

      builder.append(isSandersPrecinct() ? "Sanders" : "Clinton")
              .append(" Biggest Win: ").append(getEquivalent())
              .append(" state delegates from " + precinct)
              .append(" in ")
              .append(county);
      return builder.toString();
    }
  }
}