So, I know that there are many people with this problem and many questions about it, but I just couldn't fin a solution for this, every other thing I try to execute works, but this doesn't and I can't figure out why...
package prob3;
public class LargestPrimeFactor {
double num = 600851475143D;
double LargestPrimeFactor;
public void getLargestPrimeFactor(String [] args){
double prevPrimeFactor = 0;
do {
for(double i = 0; i < num/2; i++){
if((num % i == 0) && (num / i != 1)){
prevPrimeFactor = num;
LargestPrimeFactor = num / i;
} else {
continue;
}
}
} while(prevPrimeFactor != LargestPrimeFactor);
System.out.println("The biggest prime factor of " + num + " is " + LargestPrimeFactor);
}
}
you should define a main function to run your program. Something like:
public static void main(String[] args) {
getLargestPrimeFactor(args);
}
Related
So, I have a list of Upgrade systems for my game but it has a bug on it when I press upgrade for a second time the index out of range then pressed for the third times the index out of range gone. this whole script.
void Start()
{
newSelectedIndex = previousSelectedIndex = PlayerPrefs.GetInt("currentPlayer");
btn = Select_Player[newSelectedIndex].GetComponent<Button>();
btn.interactable = false;
Coins = M_CoinManager.instance.Coins;
for (int i = 0; i < Select_Player.Length; i++)
{
priceText[i].text = Cost_Player[i].ToString();
value_player[i] = "" + i;
Select_Player[i].SetActive(false);
buyPlayer[i] = PlayerPrefs.GetInt(value_player[i]);
}
//if(PlayerPrefs.HasKey("currentPlayer")){
selectedVehicleIndex = PlayerPrefs.GetInt("currentPlayer");
theVehicles[selectedVehicleIndex].SetActive(true);
VehicleInfo();
UpgradeButtonStatus();
}
// Update is called once per frame
void Update()
{
for (int i = 0; i < Select_Player.Length; i++)
{
buyPlayer[i] = PlayerPrefs.GetInt(value_player[i]);
if (i == buyPlayer[i])
{
Select_Player[i].SetActive(true);
upgradeBtn[i].interactable = true;
UpgradeButtonStatus();
}
else
{
upgradeBtn[i].interactable = false;
}
}
}
public void BuyCharact(int id)
{
M_SoundManager.instance.playUIsfx();
if (Cost_Player[id] <= Coins)
{
M_CoinManager.instance.AddCoins(-Cost_Player[id]);
PlayerPrefs.SetInt(value_player[id], id);
}
else
{
_CoinShake.DoShake();
Debug.Log("Does have enough coin");
}
}
public void Reset()
{
for (int i = 0; i < Select_Player.Length; i++)
{
PlayerPrefs.SetInt(value_player[i], 0);
}
}
public void Select(int id)
{
previousSelectedIndex = newSelectedIndex;
newSelectedIndex = id;
newSelectedIndex = selectedVehicleIndex;
PlayerPrefs.SetInt("currentPlayer", newSelectedIndex);
Button newbtn = Select_Player[previousSelectedIndex].GetComponent<Button>();
btn = Select_Player[newSelectedIndex].GetComponent<Button>();
btn.interactable = false;
newbtn.interactable = true;
M_SoundManager.instance.playUIsfx();
Debug.Log("Selected TypeCar" + newSelectedIndex);
}
public void nextVehicle()
{
M_SoundManager.instance.playUIsfx();
theVehicles[selectedVehicleIndex].SetActive(false);
selectedVehicleIndex = (selectedVehicleIndex + 1) % theVehicles.Length;
theVehicles[selectedVehicleIndex].SetActive(true);
VehicleInfo();
UpgradeButtonStatus();
}
public void PreviousVehicle()
{
M_SoundManager.instance.playUIsfx();
theVehicles[selectedVehicleIndex].SetActive(false);
selectedVehicleIndex--;
if (selectedVehicleIndex < 0)
{
selectedVehicleIndex += theVehicles.Length;
}
theVehicles[selectedVehicleIndex].SetActive(true);
VehicleInfo();
UpgradeButtonStatus();
}
public void VehicleInfo()
{
currLevel = _VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel;
levelText[selectedVehicleIndex].text = "Level: " + (currLevel + 1);
powerText[selectedVehicleIndex].text = "Power: " + _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[currLevel].motorPower;
brakeText[selectedVehicleIndex].text = "Brake: " + _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[currLevel].brakePower;
Debug.Log(selectedVehicleIndex);
}
public void upgradeMethod()
{
nextLevelIndex = _VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel + 1;
if (Coins >= _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[nextLevelIndex].unlockCost)
{
Coins -= _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[nextLevelIndex].unlockCost;
_VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel++;
if (_VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel < _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel.Length - 1)
{
upgradeBtnText[selectedVehicleIndex].text = "Upgrade Cost :" + _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[nextLevelIndex + 1].unlockCost;
}
else
{
upgradeBtn[selectedVehicleIndex].interactable = false;
upgradeBtnText[selectedVehicleIndex].text = "Max Level";
}
VehicleInfo();
}
}
private void UpgradeButtonStatus()
{
if (_VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel < _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel.Length - 1)
{
upgradeBtn[selectedVehicleIndex].interactable = true;
nextLevelIndex = _VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel + 1;
upgradeBtnText[selectedVehicleIndex].text = "Upgrade Cost :" + _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[nextLevelIndex + 1].unlockCost;
}
else
{
upgradeBtn[selectedVehicleIndex].interactable = false;
upgradeBtnText[selectedVehicleIndex].text = "Max Level";
}
}
and the error reference to this method :
private void UpgradeButtonStatus()
{
if (_VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel < _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel.Length - 1)
{
upgradeBtn[selectedVehicleIndex].interactable = true;
nextLevelIndex = _VehicleStats[0].carItem[selectedVehicleIndex].unlockedLevel + 1;
upgradeBtnText[selectedVehicleIndex].text = "Upgrade Cost :" + _VehicleStats[0].carItem[selectedVehicleIndex].vehicleLevel[nextLevelIndex + 1].unlockCost;
}
else
{
upgradeBtn[selectedVehicleIndex].interactable = false;
upgradeBtnText[selectedVehicleIndex].text = "Max Level";
}
}
as you can see on the update that's what I mean. after i press upgrade for third times the error stopped.
and this for the inpector
Arrays length is one higher than their highest index, but last iteration of "for" loops goes to array.length.
You need to make "for" loops to array.length-1.
I see you do "for" loops of up to array.length.
I haven't truly read thru your whole script so there might be more, but it's a typical error in my "for" loops so I think that is causing your error.
I am having an issue with my merge sort, when I print out my sortedArray it only returns [ 0.0, 0.0.....] Im not sure if there is an error in my sort code or in my print line or if it has to do with doubles. The code I am us posted below.
By calling System.out.println(toString(sortedArray) I get an even more obscure answer.
Thanks for any help.
package mergesort;
import java.util.Arrays;
import java.util.Random;
public class mergesort {
public static void main(String[] args) {
double[] array = getIntArray();
long before = System.nanoTime();
double[] sortedArray= mergeSort(array);
System.out.println("Sorting took "+ (System.nanoTime() - before) +" nanoseconds ");
System.out.println(toString(array) + "\n\n" + toString(sortedArray) + "\n main method completed in: " + (System.nanoTime() - before) + " nanoseconds.");
}
private static String toString(double[] array) {
StringBuilder sb = new StringBuilder("[ ");
double len = array.length;
for(int i = 0; i < len - 1; i++) {
sb.append(array[i] + ", ");
}
sb.append(array[(int) (len - 1)] + " ]");
return sb.toString();
}
public static double[] mergeSort(double[] array) {
if (array.length <= 1) {
return array;
}
int half = array.length / 2;
return merge(mergeSort(Arrays.copyOfRange(array, 0, half)),
mergeSort(Arrays.copyOfRange(array, half, array.length)));
}
private static double[] merge(double[] ds, double[] ds2) {
int len1 = ds.length, len2 = ds2.length;
int totalLength = len1 + len2;
double[] result = new double[totalLength];
int counterForLeft =0,counterForRight=0,resultIndex=0;
while(counterForLeft<len1 || counterForRight < len2){
if(counterForLeft<len1 && counterForRight < len2){
if(ds[counterForLeft]<= ds2[counterForRight]){
result[resultIndex++] =(int) ds[counterForLeft++];
} else {
result[resultIndex++] =(int) ds2[counterForRight++];
}
}else if(counterForLeft<len1){
result[resultIndex++] = (int) ds[counterForLeft++];
}else if (counterForRight <len2){
result[resultIndex++] =(int) ds2[counterForRight++];
}
}
return result;
}
private static double[] getIntArray() {
double[] array = new double[10000];
Random random = new Random();
for(int i = 0; i < 10000; i++) {
array[i] = (random.nextDouble() * .99999);
}
return array;
}
}
In the merge method, when copying from one of the input arrays to the results, you cast to int. For example:
result[resultIndex++] =(int) ds[counterForLeft++];
All your doubles are in the range [0...1), so the result of casting any of them to int is zero. Just get rid of those casts, and you will keep your numbers in the merge result.
As an additional tip, it is much easier to debug small problems than large ones. It failed for any size greater than 2, so you should have been debugging with size 2, not 10000.
I'm learning java and I'm having an issue with my if code not running.
In the following code I'm trying to determine if a number (variable num) is a triangle number (1,3, 6, 10 etc). The code should run through and give the "Is Triangle". However it keeps spitting out Null.
I understand this is not the most effective way to do this code, but I am trying to learn how to use Classes.
public class HelloWorld {
public static void main(String[] args) {
class NumberShape {
int num = 45;
int tri = 0;
int triplus = 0;
String triresult;
public String triangle() {
while (tri < num) {
if (tri == num) {
triresult = "Is a Triangle";
System.out.println("Is a Triangle");
} else if (tri + (triplus + 1) > num){
triresult = "Is Not a Triangle";
} else {
triplus++;
tri = tri + triplus;
}
}
return triresult;
}
}
NumberShape result = new NumberShape();
System.out.println(result.triangle());
}
}
Thanks for any help provided.
Try this code :
public class HelloWorld {
public static void main(String[] args) {
class NumberShape {
int num = 10;//Try other numbers
int tri = 0;
int triplus = 0;
int res = 0;
String triresult = "Is Not a Triangle";
int[] tab= new int[num];
public String triangle() {
//to calculate the triangle numbers
for(int i = 0; i<num; i++){
res = res + i;
tab[i]=res;
}
//To check if num is a triangle or not
for(int i = 0; i<tab.length; i++){
System.out.println(">> " + i + " : " + tab[i]);
if(tab[i]== num){
triresult = num + " Is a Triangle";
break;//Quit if the condition is checked
}else{
triresult = num + " Is Not a Triangle";
}
}
return triresult;
}
}
NumberShape result = new NumberShape();
System.out.println(result.triangle());
}
}
Hope this Helps.
Step through the loop carefully. You'll probably see that there is a case where
(tri < num)
fails, and thus you fall out of the loop, while
(tri == num)
and
(tri + (triplus + 1) > num)
both fail too, so no text gets set before you fall out.
You probably want to do your if-tests within the method on just tri, not a modification of tri, so as to reduce your own confusion about how the code is working.
I'm creating a random number generator which then sorts the digits from largest to smallest. Initially it worked but then I changed a few things. As far as I'm aware I undid all the changes (ctrl + z) but now I have errors at the points where i try to call the methods. This is probably a very amateur problem but I haven't found an answer. The error i'm met with is "method in class cannot be applied to given types"
Here's my code:
public class RandomMath {
public static void main(String[] args) {
String bigger = bigger(); /*ERROR HERE*/
System.out.println(bigger);
}
//create method for generating random numbers
public static int generator(int n){
Random randomGen = new Random();
//set max int to 10000 as generator works between 0 and n-1
for(int i=0; i<1; i++){
n = randomGen.nextInt(10000);
// exclude 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 9999, 0000
if((n==1111 || n==2222 || n==3333 || n ==4444 || n==5555)
||(n==6666 || n==7777 || n==8888 || n==9999 || n==0000)){
i--;
}
}
return n;
}
//create method for denoting the bigger number
public static String bigger(int generated){
generated = generator(); /*ERROR HERE*/
System.out.println(generated);
int[] times = new int[10];
while (generated != 0) {
int val = generated % 10;
times[val]++;
generated /= 10;
}
String bigger = "";
for (int i = 9; i >= 0; i--) {
for (int j = 0; j < times[i]; j++) {
bigger += i;
}
}
return bigger;
}
}
You have not defined a method bigger(), only bigger(int generated). Therefore, you must call your bigger method with an integer parameter.
I'm trying to write a program that asks the user to input the size of the array the user wants to create, and then asks the user to fill the array with elements, and then it should display the array with its elements and, ask the user to conduct a search for an integer. It should conduct a linear and binary search, while displaying how many probes it took to determine is the element is in the array. So far the only output i have gotten is that the element has not been found. If you could look at my code and see what the problem is, because i have tried for hours and i have changed everything i can think of. Any help would be greatly appreciated.
import java.util.Scanner;
public class Searching
{
public static int[] anArray = new int[100];
private int numberOfElements;
public int arraySize = numberOfElements;
public String linearSearch(int value)
{
int count = 0;
boolean valueInArray = false;
String indexOfValue = "";
System.out.print("The Value was Found in: ");
for(int i = 0; i < arraySize; i++)
{
if(anArray[i] == value)
{
valueInArray = true;
System.out.print(i + " ");
indexOfValue += i + " ";
}
count ++;
}
if(!valueInArray)
{
indexOfValue = " None found";
System.out.print(indexOfValue);
}
System.out.println("\nIt took " + count + " probes with a linear search to find");
return indexOfValue;
}
public void binarySearch(int value)
{
int min = 0;
int max = arraySize - 1;
int count = 0;
while(min <= max)
{
int mid = (max + min) / 2;
if(anArray[mid] < value) min = mid + 1;
else if(anArray[mid] > value) max = mid - 1;
else
{
System.out.println("\nFound a Match for " + value + " at Index " + mid);
min = max + 1;
}
count ++;
}
System.out.println("It took " + count + " probes with a binary search to find");
}
public static void main(String[] args)
{
#SuppressWarnings("resource")
Scanner scan = new Scanner(System.in);
System.out.println("Input the number of elements in your Array");
int numberOfElements = scan.nextInt();
if(numberOfElements <= 0)
{
System.exit(0);
}
int[] anArray = new int[numberOfElements];
System.out.println("\nEnter " + numberOfElements + " Integers");
for(int i = 0; i < anArray.length; i ++)
{
System.out.println("Int # " + (i + 1) + ": ");
anArray[i] = scan.nextInt();
}
System.out.println("\nThe integers you entered are: ");
for(int i = 0; i < anArray.length; i ++) // for loop used to print out each element on a different line
{
System.out.println(anArray[i]);
}
System.out.println("Which element would you like to find?");
int value = scan.nextInt();
Wee3Q2JOSHBALBOA newArray = new Wee3Q2JOSHBALBOA();
newArray.linearSearch(3);
newArray.binarySearch(value);
}
}
hmm I am not sure you are using an array the correct way, you see an Array is a set size and I dont think you can expand like they way you are doing...
Instead try setting the size of the array to certain length.
Or use vectors