I have a java program that takes the scores of 4 players and computes each player's average score when -1 is inputted. At the end of the program I need to display the highest average score out of the 4 averages, however I cannot figure out how to do this, can you guys set me in the right direction? The program looks like this when it is run: (I have also attached my code) I cannot use anything but loops.
Player 1
Enter your score: 100
Enter your score: 90
Enter your score: 80
Enter your score: 70
Enter your score: -1 (when -1 is inputted, the average score is calculated)
Average Score = 85.00
Player 2
Enter your score: 90
Enter your score: 90
etc.
etc.
import java.util.Scanner;
public class BowlingScores
{
public static void main(String[]args)
{
double score = 0;
double totalScore = 0;
double count = 0;
Scanner input = new Scanner(System.in);
for (int player = 1; player <= 4; player++){
System.out.printf("\nPlayer %d\n", player);
do{
System.out.println("Enter Your Score: ");
totalScore = totalScore + score;
score = input.nextDouble();
count++;
} while (score != -1);
if (score == -1){
count--;
System.out.printf("Average Score = %.2f\n",totalScore/count);
count = 0;
score = 0;
totalScore = 0;
}
}
}
}
Just keep track of the highest average in another variable. Then in your score == -1 condition check to see if the current average is higher than the highest average, and if so make current the new highest. Then after your for loop you could print out the highest average.
You can add a copy of the highest at the top of your code like this double highest = 0 then in your for loop have a way to replace it if the current average is higher.
if(score > highest){
highest=score;
}
Then at the -1 you can either reset it to 0 or keep it going.
public static void main(String[] args) {
final List<Double> allAverages = new ArrayList<>();
double score = 0;
double totalScore = 0;
double avg = 0;
int count = -1;
Scanner input = new Scanner(System.in);
for (int player = 1; player <= 4; player++) {
System.out.printf("\nPlayer %d\n", player);
do {
System.out.println("Enter Your Score: ");
totalScore = totalScore + score;
score = input.nextDouble();
count++;
} while (score != -1);
avg = totalScore / count;
System.out.printf("Average Score = %.2f\n", avg);
allAverages.add(totalScore / count);
score = 0;
totalScore = 0;
count = -1;
}
System.out.println("The highest is : " + Collections.max(allAverages));
}
Here a list of the modifications I did to your code to get it working :
The variable count now start at -1, so there is no need to do count-- when we exit the loop.
I've added a List that keep a track of all the averages.
I've removed the validation if(count == -1) after the loop as the only way to exit the loop is to have count == -1 so we already know it is the actual value.
To retrieve the maximum of all averages, I use Collections.max(allAverages).
Take average of all 4 players and store into one array. Then check for the largest number in array.
double[] highest = new double[4];
for(int i=0; i<4; i++){
highest[i] = totalScore/count;
}
if(highest[0]>highest[1] && highest[0]>highest[2] && highest[0]>highest[3])
System.out.println("highest" + highest[0]);
else if(highest[1]>highest[0] && highest[1]>highest[2] && highest[0]>highest[3])
System.out.println("highest" + highest[1]);
else if(highest[2]>highest[0] && highest[2]>highest[1] && highest[0]>highest[3])
System.out.println("highest" + highest[2]);
else System.out.println("highest" + highest[3]);
public static void main(String[]args) {
double bestScore = 0;
int bestPlayer = 1;
Scanner input = new Scanner(System.in);
for (int player = 1; player <= 4; player++){
System.out.printf("\nPlayer %d\n", player);
int count = 0; // does not need to be double
double totalScore = 0;
do {
System.out.println("Enter Your Score: ");
double score = input.nextDouble();
if (score != -1) {
totalScore += score;
count++;
}
} while (score != -1);
double averageScore = totalScore / count;
if (averageScore > bestScore) {
bestScore = averageScore;
bestPlayer = player;
}
System.out.printf("Average Score = %.2f\n", averageScore);
}
System.out.printf("Best Average Score = %.2f, best player = %d\n", bestScore, bestPlayer);
}
Just keep a variable to record the top average score every time as in topAverage in my example below. The code is same as your's except I changed the variable names for my readability.
public static void main(String[] args) throws NumberFormatException,
IOException {
double currentScore = 0;
double totalScore = 0;
int numScores = 0;
double averageScore = 0;
double topAverage = 0;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
for (int i = 0; i < 4; i++) {
do {
System.out.println("Enter Score");
currentScore = Double.parseDouble(br.readLine());
totalScore = totalScore + currentScore;
numScores += 1;
} while (currentScore != -1);
numScores-=1;
totalScore+=1;
averageScore = totalScore / numScores;
System.out.println("Average Score is " + averageScore);
if (topAverage < averageScore) {
topAverage = averageScore;
}
currentScore = 0;
totalScore = 0;
numScores = 0;
}
System.out.println("Top Average is " + topAverage);
}
Edit
#Andrei Nikolaenko posted the same answer before me, so consider that answer, I am adding this edit because I want to mention that my browser did not refresh on time to show me that the answer has already been posted.
Related
This question already has answers here:
What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?
(26 answers)
Closed 3 years ago.
Here is my code:
package project4;
import java.util.Scanner;
public class ScoreAnalyzer {
//#OfScores is the length of the scores array
public static int numberOfScores = 0;
public static double[] scores = new double[numberOfScores];
public static double sum = 0.0;
public static double place = 0.0;
//Of sorted list
public static double[] sortedList = new double[numberOfScores];
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the number of scores you'd like to average: ");
numberOfScores = input.nextInt();
scores = new double[numberOfScores];
for (int count = 0; count < scores.length; count++) {
System.out.print("Enter score #" + count + ": ");
place = input.nextDouble();
scores[count] = place;
System.out.println("The score of " + scores[count] + " is " + getGrade(count));
}
sumOfScores();
System.out.println("The average of these scores is: " + averageOfScores());
sort();
System.out.println("The sorted list of scores (above average scores are "
+ "marked with an\n" + "asterisk '*'): " + sortedList[numberOfScores]);
}
public static char getGrade(int i) {
//this
if (scores[i] >= 90.0) {
return 'A';
}
if (scores[i] >= 80.0) {
return 'B';
}
if (scores[i] >= 70.0) {
return 'C';
}
if (scores[i] >= 60.0) {
return 'D';
}
else {
return 'F';
}
}
public static double sumOfScores() {
//sum = 0.0;
for (int i = 0; i < numberOfScores; i++) {
sum += scores[i];
}
return sum;
}
public static double averageOfScores() {
double average = sum / numberOfScores;
return average;
}
public static void sort() {
for (int i = 0; i < scores.length - 1; i++) {
// Find the minimum in the list[i..list.length-1]
double currentMin = scores[i];
int currentMinIndex;
currentMinIndex = i;
for (int j = i + 1; j < scores.length; j++) {
if (currentMin > scores[j]) {
currentMin = scores[j];
currentMinIndex = j;
}
}
// Swap list[i] with list[currentMinIndex] if necessary;
if (currentMinIndex != i) {
sortedList[currentMinIndex] = scores[i];
scores[i] = currentMin;
}
}
}
}
The program's purpose is to prompt the user for the number of scores to be entered first, then allow the user to enter that number of scores. As each score is entered, the program should give them a grade for each score inputted. The program then should use a method to find the sum, pass that sum into a method that finds the average, and sort the array in a method.The sorted array should be displayed along with the average and each score which is above the average should be noted with an asterisk beside it.
When I run the program, I am able to enter the number of scores I want to average, input those scores, obtain the sum and average but I'm having problem sorting it to have the asterisk to above average numbers:
Enter the number of scores you'd like to average: 3
Enter score #0: 90
The score of 90.0 is A
Enter score #1: 80
The score of 80.0 is B
Enter score #2: 70
The score of 70.0 is C
The average of these scores is: 80.0
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2
at project4.ScoreAnalyzer.sort(ScoreAnalyzer.java:86)
at project4.ScoreAnalyzer.main(ScoreAnalyzer.java:32)
There is a problem with the terminating condition of your for loop. Since the array index starts with 0, the highest index will go up to 2 for an array of size 3. However, count, using which you are accessing elements of scores[], is going up to 3 in your for loop and that is the reason for the ArrayOutOfBoundsException. Change the for loop as follows:
for (int count = 0; count < scores.length ; count++)
I have a question which asks me to enter some exam score to find the highest and the lowest score overall. (Highlighted question.)
float sum = 0, score1, score2 = 0, score3 = 0;
do
{
System.out.println("Enter a score [negative score to quit]: ");
Scanner Score1 = new Scanner(System.in);
score1 = Score1.nextFloat();
if (score1>score2)
{
max = score1;
min = score2;
}
else if(score1<score2)
{
max = score2;
min = score1;
}
else{
score3 = score2;
}
}
}
while (score1>=0);
System.out.printf("Minimun Score = %.0f\n", min);
System.out.printf("Maximum Score = %.0f\n", max);
Enter a score [negative score to quit]:
99
Enter a score [negative score to quit]:
1
Enter a score [negative score to quit]:
6
Enter a score [negative score to quit]:
5
Enter a score [negative score to quit]:
-1
Minimum Score = 5
Maximum Score = 6
BUILD SUCCESSFUL (total time: 7 seconds)
The problem is it only compares the latest 2 score that I entered.
How do i fix this?
The do-while logic may not work in the above code. see the working code below..
float sum = 0, score = 0;
float min = 0, max = 0, ave = 0;
Scanner stdInput = new Scanner(System.in);
System.out.println("Enter the scores: ");
min = max = score = stdInput.nextFloat();
do {
System.out.println("Enter a score [negative score to quit]: ");
if (score > max) {
max = score;
}else if (score < min) {
min = score;
}
sum += score;
// Read the input here so that, the code does not process the negative input.
score = stdInput.nextFloat();
} while (score >= 0);
System.out.println(min);
System.out.println(max);
Logic in if-else ladder is incorrect.
You may find following useful:
class Test
{
public static void main (String[] args) throws java.lang.Exception
{
try(Scanner Score1 = new Scanner(System.in))
{
//Marks are in range of 0-100
float curNum, max = -1, min = 101, sum = 0, sumsq = 0;
boolean flg = true;
while(flg)
{
System.out.println("Enter a score [negative score to quit]: ");
curNum = Score1.nextFloat();
if(curNum<0) break;
if(max < curNum) max = curNum;
if(min > curNum) min = curNum;
sum += curNum;
sumsq += (curNum*curNum);
}
System.out.printf("Minimun Score = %.0f\n", min);
System.out.printf("Maximum Score = %.0f\n", max);
}
}
}
You can find it working here
The first part of the exercise was to calculate the test score average. The next problem asked me to build off this problem and calculate the minimum and maximum. Can anyone help me? This is my code so far.
import java.util.Scanner;
import java.io.*;
import java.text.DecimalFormat;
public class hw
{
public static void main ( String[] args )
{
int maxGrade;
int minGrade;
int count=0;
int total=0;
final int SENTINEL = -1;
int score;
Scanner scan = new Scanner( System.in);
System.out.println( "To calculate the class average, enter each test
score.");
System.out.println( "When you are finished, enter a -1.");
System.out.print( "Enter the first test score > ");
score = scan.nextInt();
while (score != SENTINEL )
{
total += score;
count ++;
System.out.print("Enter the next test score > ");
score = scan.nextInt();
}
if (count != 0)
{
DecimalFormat oneDecimalPlace = new DecimalFormat("0.0");
System.out.println( "\nThe class average is "
+ oneDecimalPlace.format( (double) (total) / count ));
}
else
System.out.println("\nNo grades were entered");
}
}
in your while loop, you can compare the current score to the maximum and the minimum.
while (score != SENTINEL )
{
total += score;
count ++;
if(score > maxGrade)
maxGrade = score;
if(score < minGrade)
minGrade = score;
System.out.print("Enter the next test score > ");
score = scan.nextInt();
}
You also need to set the max and min (when declaring them) to their "opposite" value:
int maxGrade = Integer.MIN_VALUE;
int minGrade = Integer.MAX_VALUE;
So here is my code:
package e7;
import java.util.Scanner;
public class Q1 {
public static void main(String[] args)
{
double[] scores = new double[10];
double sum = 0.0D;
int count = 0;
Scanner sc = new Scanner(System.in);
do {
System.out.print("Enter a new score (-1 to end): ");
scores[count] = sc.nextDouble();
if (scores[count] >= 0.0D)
sum += scores[count];
}
while (scores[(count++)] >= 0.0D);
System.out.println("The total number of scores is: " + count );
double average = sum / (count - 1);
int numOfAbove = 0;
int numOfBelow = 0;
for (int i = 0; i < count - 1; i++) {
if (scores[i] >= average)
numOfAbove++;
else
numOfBelow++;
}
System.out.printf("Average is " + "%.2f\n",average);
System.out.println("Number of scores above or equal to the average " + numOfAbove);
System.out.println("Number of scores below the average " + numOfBelow);
}
}
How do make it display the correct number of scores calculated? If I input 2 numbers and then do the -1 one to end it keeps saying 3 scores. Should only be two. How do I fix this? Thanks
System.out.println("The total number of scores is: " + count );
You probably want:
System.out.println("The total number of scores is: " + (count - 1));
You could also change your loop from a do while to a while loop as follows,
while (true) {
System.out.print("Enter a new score (-1 to end): ");
double tempDouble = sc.nextDouble();
if (tempDouble >= 0.0D)
scores[count] = tempDouble;
sum += scores[count];
count++;
else
break;
}
That way as if your double input isn't correct it would break out of the while loop when the user entered -1. You might have to tweak it a bit for your use case.
So I am attempting to write a program where you enter your grades, totals them up, averages, and then drops the lowest grade. This is what I have so far, however, when I try to run the program I receive the average of 92 when I enter the values 100,100,75.
The average should be printing as 100. What is wrong with the code?
Thanks in advance!
import java.util.Scanner;
public class l3_drop_lowest_slide36 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
double grade;
int count;
double minGrade;
double sumGrade;
double average;
System.out.println("Begin entering grades below. When done, type -1.");
System.out.println();
count = 0;
sumGrade = 0;
grade = 0;
minGrade = 100;
while ( grade != -1 ) {
sumGrade += grade;
count++;
System.out.print("Grade: ");
grade = input.nextDouble();
}
if ( grade < minGrade ) {
minGrade = grade;
}
if ( grade == -1 ) {
sumGrade = sumGrade - minGrade;
count = count - 1;
average = (sumGrade / count);
System.out.print("Your average is: " +average);
}
}
}
You can do something like this:
while ( grade != -1 ) {
sumGrade += grade;
count++;
System.out.print("Grade: ");
grade = input.nextDouble();
if(grade < minGrade && grade != -1)
minGrade = grade;
}
sumGrade = sumGrade - minGrade;
count = count - 1;
average = (sumGrade / count);
System.out.print("Your average is: " +average);
This way you are dropping out the minimum grade.
You are reading grade = input.nextDouble(); first and then checking if it's -1. Your while loop runs 4 times and not 3. So, essentially your count is 4 and not 3. Your minimum grade is -1 (the last input value) and not 75. Fix that logic and you should be good.
Your
if ( grade < minGrade ) {
minGrade = grade;
}
should be inside your
while ( grade != -1 ) {
}
Because when you get -1, -1 < 100 and minGrade = -1.
sumGrade - minGrade = (100+100+75) - (-1) = 276
And when u divide 276/3 = 92.