So I have everything working fine up until the point in which I need to search. I'm really new to this so my code is probably awful I'm sorry in advance. Anyway, its a user input array, and the user should be able to search for a number in an array. Im getting the error for a duplicate variable on line 50 (int i, get 1).
import java.util.Scanner;
class SearchingSorting {
public static void main (String[] args) {
Scanner input = new Scanner(System.in);
System.out.println ("How many numbers would you like to input?");
int num = input.nextInt();
double[] array = new double[num];
for (int i = 0; i < num; i++) {
System.out.println ("Input number " + (1 + i) + ":");
array[i] = input.nextDouble();
}
for (double temp1 : array){
System.out.print (temp1 + "\t");
}
input.close();
int pass;
int i;
int hold;
for(pass = 1; pass < array.length; pass++)
{
for(i = 0; i < array.length - 1; i++)
{
if(array[i] > array[i+1])
{
hold = (int) array[i];
array[i] = array[i+1];
array[i+1] = hold;
}
}
System.out.println("\nSorted number is: ");
for(i = 0; i < array.length; i++)
System.out.print(" " + array[i]);
}
int i, get1;
Scanner keyboard = new Scanner(System.in);
int[] numbers = new int[10];
for(i = 0; i < numbers.length; i++)
{
numbers[i] = i * 10;
}
System.out.print("Enter search number: ");
get1 = keyboard.nextInt();
SearchMethod(numbers, get1);
}
public static void SearchMethod(int[] num, int get2)
{
int i ;
boolean j = false;
for(i = 0; i < num.length; i++)
{
if(num[i] == get2)
{
j = true;
break;
}
}
if(j == true)
System.out.println(get2 + " is found at num[" + i + "]");
else
System.out.println(get2 + " is not found in an array");
}
}
You are trying to declare a new variable with the same name ("i") in the same scope.
Rename your variable i on line 50.
Related
My goal is to print out a user input value (and its corresponding index) if it appears 1 or more times in a random generated array of 50 integers. If I search the array for a value, and it happens to appear more than once, however, only one location of the element is printed, and then the if-else statement is executed. If I remove the break at the end of the third for loop, the whole thing falls apart. I've attached an image but here is the part of it that is giving me an issue. Apologies if the code is not clean, I'm very new.
public static void main(String[] args) {
System.out.println("IDS201 HW3:\n");
System.out.println("1. Generate 50 random integer unsorted list.\n");
Scanner stdin = new Scanner(System.in);
int[] randomNumbers = new int[50];
for(int index = 0; index < randomNumbers.length; index++) {
randomNumbers[index] = (int) (Math.random()*100);
}//end for
int count = 0;
for(int i = 0; i < randomNumbers.length; i++) {
System.out.print(randomNumbers[i] + ",");
count++;
if(count == 10) {
System.out.println();
count = 0;
}
}//end for
System.out.println("\nSearch value?");
int x = stdin.nextInt();
int i;
for(i = 0; i < randomNumbers.length; i++) {
if(randomNumbers[i] == x)
break;}
if (i != randomNumbers.length) {
System.out.println("\nFound " + x + " in array [" + i + "]");}
else {
System.out.println(x + " is not in the list");}
{int temp;
int size = randomNumbers.length;
for(i = 0; i<size; i++ ){
for(int j = i+1; j<size; j++){
if(randomNumbers[i]>randomNumbers[j]){
temp = randomNumbers[i];
randomNumbers[i] = randomNumbers[j];
randomNumbers[j] = temp;
}
}
}
System.out.println("\nSmallest element of the array is: " + randomNumbers[0]);}
System.out.println("\n3. Sort the list:");
int size = randomNumbers.length;
for(i=0; i<size; i++)
{
for(int j=i+1; j<size; j++)
{
if(randomNumbers[i] > randomNumbers[j])
{
int temp = randomNumbers[i];
randomNumbers[i] = randomNumbers[j];
randomNumbers[j] = temp;
}
}
}
System.out.print("Now the Array after Sorting is :\n\n");
int count1 = 0;
for(i=0; i<size; i++)
{
System.out.print(randomNumbers[i]+ ",");
count++;
if(count == 10) {
System.out.println();
count = 0;
}
}
}
}
if statement in for loop
Implementing the comments to your question:
import java.util.Scanner;
public class NumCount {
private static final int RANDOM_NUMBER_COUNT = 50;
private static void display(int[] randomNumbers) {
int count = 0;
for (int i = 0; i < RANDOM_NUMBER_COUNT; i++) {
System.out.print(randomNumbers[i] + ",");
count++;
if (count == 10) {
System.out.println();
count = 0;
}
}
}
private static int[] generateRandomNUmbers() {
int[] randomNumbers = new int[RANDOM_NUMBER_COUNT];
for (int index = 0; index < RANDOM_NUMBER_COUNT; index++) {
randomNumbers[index] = (int) (Math.random() * 100);
}
display(randomNumbers);
return randomNumbers;
}
private static int search(int[] randomNumbers, int x) {
int i;
int count = 0;
for (i = 0; i < randomNumbers.length; i++) {
if (randomNumbers[i] == x) {
System.out.println("\nFound " + x + " in array [" + i + "]");
count++;
}
}
return count;
}
private static int[] sort(int[] randomNumbers) {
int size = randomNumbers.length;
for (int i = 0; i < size; i++) {
for (int j = i + 1; j < size; j++) {
if (randomNumbers[i] > randomNumbers[j]) {
int temp = randomNumbers[i];
randomNumbers[i] = randomNumbers[j];
randomNumbers[j] = temp;
}
}
}
return randomNumbers;
}
/**
* Start here.
*/
public static void main(String[] args) {
System.out.println("IDS201 HW3:\n");
System.out.println("1. Generate " + RANDOM_NUMBER_COUNT + " random integer unsorted list.\n");
int[] randomNumbers = generateRandomNUmbers();
System.out.print("\n2. Search value? ");
Scanner stdin = new Scanner(System.in);
int x = stdin.nextInt();
int count = search(randomNumbers, x);
if (count == 0) {
System.out.println(x + " is not in the list");
}
System.out.println("\n3. Sort the list:");
sort(randomNumbers);
System.out.print("Now the Array after Sorting is :\n\n");
display(randomNumbers);
}
}
Of-course there is no need to search for the smallest number because it will be the first element in the sorted array. Hence I removed that part of your code.
I need to take input from the user and if the user enters string the program should keep integer in descending order and the position of the string should be in constant position. I am not being able to keep only integer in descending order.
public class sort {
public static void main(String[] args) {
int num;
int i, j, temp;
String nu;
int y;
Scanner input = new Scanner(System.in);
System.out.println("Enter the number of character to be sort:");
String num = input.nextLine();
int length = num.length();
String result = "";
for (i = 0; i < length; i++) {
Character character = num.charAt(i);
if (Character.isDigit(character)) {
result += character;
}
}
int array[] = new int[num];
System.out.println("Enter " + num + " character ");
for (i = 0; i < num; i++)
array[i] = input.nextInt();
for (i = 0; i < (num - 1); i++) {
for (j = 0; j < num - i - 1; j++) {
if (array[j] < array[j + 1]) {
temp = array[j];
array[j] = array[j + 1];
array[j + 1] = temp;
}
}
}
System.out.println("Sorted list of integers:");
for (i = 0; i < num; i++)
System.out.println(array[i]);
}
}
I've made some modifications to your code that might help. For one, Integer.ParseInt works better than nextInt() because nextInt() leaves a carriage return on nextLine(). Also I feel a while loop would work better for your bubble sort algorithm.
import java.util.*;
public class sort {
public static void main(String[] args) {
int num;
int i, temp;
String nu;
int y;
Scanner input = new Scanner(System.in);
System.out.println("Enter the number of character to be sort:");
num = Integer.ParseInt(input.nextLine());
int[] arr = new int[num];
System.out.println("Enter " + num + " character ");
for (i = 0; i < num; i++)
arr[i] = Integer.ParseInt(input.nextLine());
int swaps;
while (swaps == 0) {
swaps = 0;
for (i = 0; i < arr.Length; i++) {
if (arr[j] < arr[i + 1]) {
temp = arr[i];
arr[i] = arr[i + 1];
arr[i + 1] = temp;
swaps++;
}
}
}
System.out.println("Sorted list of integers:");
for (i = 0; i < num; i++)
System.out.println(array[i]);
}
}
I changed a few things. First of all, you declared num twice, and had a String = input.nextInt() which doesn't match. The try...catch checks if it's an int input, otherwise it converts it from a char to an int. Your algorithm to put them in descending order worked fine, but populating the array wasn't working.
import java.util.InputMismatchException;
import java.util.Scanner;
public class sort {
public static void main(String []args) {
int i, j, temp;
int y;
Scanner input = new Scanner(System.in);
System.out.println("Enter the number of character to be sort:");
String num = input.nextLine();
int length = Integer.parseInt(num);
String result = "";
int array[] = new int[length];
System.out.println("Enter " + num + " character ");
for (i = 0; i < length; i++) {
try{
array[i]=input.nextInt();
}catch(InputMismatchException e){
Character c = input.next().charAt(0);
array[i]=(int)(c.charValue());
}
}
for (i = 0; i < ( length- 1 ); i++) {
for (j = 0; j < length - i - 1; j++) {
if (array[j] < array[j+1])
{
temp = array[j];
array[j] = array[j+1];
array[j+1] = temp;
}
}
}
System.out.println("Sorted list of integers:");
for (i = 0; i < length; i++)
System.out.println(array[i]);
}
}
I'm a beginner at java and I have a hopefully simple question.
I can get the numbers in order, but only a certain amount of numbers are added to the array. When there is a number less than the smallest number, it replaces that smallest number (the previous smallest gets removed from array). What can I do so that all of the array spots can be filled in?
public class apples {
public static void main(String[] args) {
System.out.print("How many numbers: ");
int num=IO.readInt();
double array[]=new double[num];
double temp;
boolean fixed=false;
while (fixed==false){
fixed=true;
for(int j=0; j<num;j++){
double x = IO.readDouble();
array[j] = x;
for (int i = 0; i < ( num - 1 ); i++) {
for (j = 0; j < num - i - 1; j++) {
if (array[j] > array[j+1]) {
temp = array[j];
array[j] = array[j+1];
array[j+1] = temp;
fixed=false;
}
}
}
System.out.println("Sorted list of integers:");
for (int i = 0; i < num; i++)
System.out.println(array[i]);
}
}
}
}
First read in the numbers, then sort the array (and it's an array of double not int). Something like,
public static void main(String[] args) {
System.out.print("How many numbers: ");
int num = IO.readInt();
double array[] = new double[num];
for (int j = 0; j < num; j++) {
System.out.printf("Please enter double %d:%n", j + 1);
array[j] = IO.readDouble();
}
System.out.println("unsorted array: " + Arrays.toString(array));
Arrays.sort(array); // <-- or however you want to sort the array.
System.out.println("sorted array: " + Arrays.toString(array));
}
public static void main(String[] args) {
System.out.print("How many numbers: ");
int num = IO.readInt();
double array[] = new double[num];
for (int i = 0; i < num; i++) {
System.out.print("["+i+"]Please enter your double");
array[i] = IO.readDouble();
}
//Sort
double temp = 0;
for (int i = 0; i < num - 1; i++) {
for (int j = i + 1; j < num ; j++) {
if (array[j] > array[j]) {
temp = array[i];
array[i] = array[j];
array[j] = temp;
}
}
}
//Result
for(int i = 0; i < array.length; i++){
System.out.print(array[i] + " ");
}
}
import java.util.*;
import java.lang.*;
import java.io.*;
public class Main
{
public static void main (String[] args) throws java.lang.Exception
{
Scanner sc =new Scanner(System.in);
int n =sc.nextInt();
int arr[]=new int [n];
for (int i =0;i<n;i++){
arr[i]=sc.nextInt();}
Arrays.sort(arr);
//if(n%2==0){median}
System.out.println( Arrays.toString(arr));
}
}
This is what i have so far but the output for both arrays is the same randomly generated numbers instead of different ones for each array.
import java.util.Scanner;
public class Prog2_b {
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in);
System.out.println("Program #2b, Breanna Bergado, mascID 1885");
System.out.println("Please enter number of elements for a 1D array:");
int userVal = scnr.nextInt();
//System.out.println(((Object)userVal).getClass().getName();
double[] array = new double[userVal];
double [] array2 = new double[userVal];
double dotProd = 0;
for(int i = 0; i < userVal; i++) {
array[i] = Math.random();
array2[i] = Math.random();
}
for (int j = 0; j < 2; j++){
System.out.println("a"+(j+1)+"[]");
System.out.println("----------------");
for (int i = 0; i < userVal; i++) {
System.out.println(array[i] + " ");
}
System.out.println();
}
for(int i = 0; i < userVal; i++) {
dotProd = dotProd + array[i]* array2[i];
}
System.out.println("Dot Product is " + dotProd);
}
}
You should update your printing logic to:
for (int i = 0; i < userVal; i++) {
System.out.println(array[i] + " ");
}
System.out.println();
for (int j = 0; j < userVal; j++) {
System.out.println(array2[j] + " ");
}
Your current logic just prints the first array twice. You could also use nested arrays as one of the comments suggested, but the above code will work with what you have so far.
This is my code for the Bubble Sort. I cannot get the actual sorted values to output. The program reads the inputted numbers, but does not print it sorted.
I'm not sure what I have to do to make them sort.
Any advice or suggestions would be helpful.
package sortingalgorithm2;
import java.util.Scanner;
public class Main {
/**
* #param args the command line arguments
*/
public static void main(String[] args)
{
Scanner read = new Scanner (System.in);
int[] num = new int[15];
int size = 15;
System.out.println("Enter 15 numbers: ");
for (int i=0; i <= size-1; i++)
{
num[i] = read.nextInt();
}
for (int i=0; i <= size-1; i++)
{
if (num[i] >=1 && num[i] <= 1000)
{
System.out.println("The numbers you entered are: ");
System.out.println(+num[0]);
System.out.println(+num[1]);
System.out.println(+num[2]);
System.out.println(+num[3]);
System.out.println(+num[4]);
System.out.println(+num[5]);
System.out.println(+num[6]);
System.out.println(+num[7]);
System.out.println(+num[8]);
System.out.println(+num[9]);
System.out.println(+num[10]);
System.out.println(+num[11]);
System.out.println(+num[12]);
System.out.println(+num[13]);
System.out.println(+num[14]);
}
else
{
System.out.println("Data input is invalid. Enter a number between "
+
"1 and 1000.");
break;
}
}
BubbleSort (num);
for (int i=0; i < num.length; i++)
{
System.out.println("The sorted numbers are: ");
System.out.print(num[i]+ " ");
}
}
private static void BubbleSort(int[] num)
{
for (int i=0; i <= num.length; i++)
for (int x=1; x <= num.length; x++)
if (num[x] > num[x+1])
{
int temp = num[x];
num[x] = num[x+1];
num[x+1] = temp;
}
}
}
Try this Bubble sort :
private static void BubbleSort(int[] num) {
for (int i = 0; i < num.length; i++) {
for (int x = 1; x < num.length - i; x++) {
if (num[x - 1] > num[x]) {
int temp = num[x - 1];
num[x - 1] = num[x];
num[x] = temp;
}
}
}
}
You are printing the actual numbers in the order the user entered. Try this instead:
int[] sortedNumbers = new int[15];
sortedNumbers = BubbleSort (num);
for (int i=0; i < sortedNumbers.length; i++)
{
System.out.println("The sorted numbers are: ");
System.out.print(sortedNumbers[i]+ " ");
}
public static int[] BubbleSort(int [] num)
{
int temp;
for (int i=1; i<num.length; i++)
{
for(int j=0; j<num.length-i; j++)
{
if (num[j] > num [j+1])
{
temp = num [j];
num [j] = num [j+1];
num [j+1] = temp;
}
}
}
return num;
}
Try this :
for (int i = 0; i < num.length; i++) {
for (int j = i + 1; j < num.length; j++) {
if (num[i] > num[j]) {
num[i] = num[i] + num[j] - (num[j] = num[i]);
}
}
}
you are passing the array variable num (which is not static) to BubbleSort()(which does not returns a value and shadows the global num variable with its own) and trying to use the same num variable to access your sorted array from your main method which is not right.
The genuine fix to this is to declare your variable num as static just before the main method( in the class declaration). So I have made the changes in the program and here is the solution.
import java.util.Scanner;
public class sol {
static int num [] =new int [15]; //declaring num as static in the class definition.
public static void main(String[] args)
{
Scanner read = new Scanner (System.in);
int size = 15;
System.out.println("Enter 15 numbers: ");
for (int i=0; i <= size-1; i++)
{
num[i] = read.nextInt();
}
read.close();
/*for (int i=0; i <= size-1; i++)
{
if (num[i] >=1 && num[i] <= 1000)
{
System.out.println("The numbers you entered are: ");
System.out.println(+num[0]);
System.out.println(+num[1]);
System.out.println(+num[2]);
System.out.println(+num[3]);
System.out.println(+num[4]);
System.out.println(+num[5]);
System.out.println(+num[6]);
System.out.println(+num[7]);
System.out.println(+num[8]);
System.out.println(+num[9]);
System.out.println(+num[10]);
System.out.println(+num[11]);
System.out.println(+num[12]);
System.out.println(+num[13]);
System.out.println(+num[14]);
}
else
{
System.out.println("Data input is invalid. Enter a number between "
+
"1 and 1000.");
break;
}
}*/ //I have disabled this just to check with the sort method.
BubbleSort ();//no need to pass the array as it is static and declared as a //class variable hence can be used to by all the methods of that class
System.out.println("The sorted numbers are: ");
for (int i=0; i < num.length; i++)
{
System.out.print(num[i]+ " ");
}
}
private static void BubbleSort()
{
for (int i=0; i < num.length; i++)// required changes in the looping
for (int x=0; x < num.length-i-1; x++)
if (num[x] > num[x+1])
{
int temp = num[x];
num[x] = num[x+1];
num[x+1] = temp;
}
}
}