I can’t seem the get the right amount of votes for the user inputted name and I can’t figure out how to get the most popular name declared as the winner. I do get how many times I’ve voted for someone but it’s not always right. Sometimes I get an ArrayIndexOutOfBounds Exception error and I think it has to do something with the Candidate get and Vote get print in the end.
This is how it supposed to be.
That’s how I managed to do it so far.
public class JavaApplication16 {
public static void main(String[] args) {
ArrayList<String> Names = new ArrayList<String>();
ArrayList<Integer> Votes = new ArrayList<Integer>();
Scanner input = new Scanner(System.in);
System.out.println("Enter the name you wish to vote for: ");
String addName = input.nextLine();
while (addName.length() != 0) {
if (Names.contains(addName)) { // Name already in the array
int i = Names.indexOf(addName); // Add some code to find the index of the name in the Names array
Integer j = Votes.get(i); // Find out how many votes they currently have
j++; // Increment it by 1
Votes.set(i, j); // Put the new number of votes back into the Votes array at the correct index
//Votes.indexOf(addName);// Increment the contents of the Votes array at the same index
//break;
}
if (addName.equals("-0")) {
System.out.println("List of the Candidates");
break;
} else { // Name not in the array
Names.add(addName); // Add the name to the end of the list
Votes.add(1); // They have one vote so far, so set their vote count to 1
}
addName = input.nextLine();
}
//End of the while loop to vote
//A List to remove the duplicates from the Name list
ArrayList<String> Candidate = new ArrayList<String>();
for (String nam : Names) {
if (!Candidate.contains(nam)) {
Candidate.add(nam);
}
}
for (int t = 0; t < Candidate.size(); t++) {
}
for (int i = 0; i < Names.size(); i++) {
}
for (int j = 0; j < Votes.size(); j++) {
} // The following is a basic example - you could use a for loop and make the output look better
System.out.println(Candidate.get(0) + " recieved " + (Votes.get(0) + " vote. "));
System.out.println(Candidate.get(1) + " recieved " + (Votes.get(1) + " vote. "));
System.out.println(Candidate.get(2) + " recieved " + (Votes.get(2) + " vote. "));
System.out.println(Candidate.get(3) + " recieved " + (Votes.get(3) + " vote. "));
// Code to find out the highest amount of votes
System.out.println("AND THE WINNER IS");
System.out.println(Collections.max(Names));
System.out.println(Collections.max(Votes));
}
}
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Answer
You use illegal data stryctyre for your goal. You use List, but you have to count the votes for each name. So you have to use Map<String, Integer> where key is the name and value is the amount of votes.
Additionally, you have to sort these names by votes. So you could create a new list with all entries form this map and then sort these names by votes desc. But I prefer to use another data structure PriorityQueue tha internally sorts the entries.
public static void main(String... args) {
System.out.println("#######################################");
System.out.println("# Enter the votes, one vote per line. #");
System.out.println("# End with either -1 or an empty line.#");
System.out.println("#######################################");
System.out.println();
Scanner scan = new Scanner(System.in);
Map<String, Integer> votes = new HashMap<>();
while (true) {
String name = scan.nextLine().trim();
if (name.isEmpty() || "-1".equals(name))
break;
votes.put(name, votes.getOrDefault(name, 0) + 1);
}
if (votes.isEmpty())
System.out.println("No Votes.");
else {
final Comparator<Map.Entry<String, Integer>> sortByVotesDesc = (one, two) -> Integer.compare(two.getValue(), one.getValue());
Queue<Map.Entry<String, Integer>> queue = new PriorityQueue<>(sortByVotesDesc);
queue.addAll(votes.entrySet());
Map.Entry<String, Integer> winner = queue.element();
while (!queue.isEmpty()) {
Map.Entry<String, Integer> vote = queue.remove();
System.out.format("%s received %d votesn", vote.getKey(), vote.getValue());
}
System.out.println("------------------------");
System.out.format("The Winner is %s with %d votesn", winner.getKey(), winner.getValue());
}
}
Demo
####################################### # Enter the votes, one vote per line. # # End with either -1 or an empty line.# ####################################### Sam Peter James Sam Sam Peter Sam Sam received 4 votes Peter received 2 votes James received 1 votes ------------------------ The Winner is Sam with 4 votes