We Keep Coding

Count and print even flowers

We have n number of flowers that can be black or white. We have m number of months. At the end of each month, if the number of white flowers is even, we print B for the number of roses that are even, and print F for the rest of the characters.For example:(W=white,B=black)
input:3(n) 2(m)
WBW
BBW
output:FBB
My code just work well just for this example and dont give true answer for other examples.
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter number of flowers: ");
int flower = input.nextInt();
System.out.println("Enter number of months : ");
int month = input.nextInt();
String[] arr = new String[month];
char ch = ' ';
int count = 0;
for (int j = 0; j < month; j++)
arr[j] = input.next();
for (int i = 0; i < month; i++) {
char[] s = arr[i].toCharArray();
for (int j = 0; j < flower; j++) {
if (s[j] == 'W') {
count++;
}
}
if (count % 2 == 0) {
for (int k = 0; k < flower - count; k++) {
System.out.print('F');
}
for (int b = 1; b <= count; b++) {
System.out.print('B');
}
}
}
}
}

In your for loop
for (int j = 0; j < flower; j++) {
if (s[j] == 'W') {
count++;
}
}
We must remember what s is referring to, char[] s = arr[i].toCharArray(); which means that s will not have a length of flower but will have a length of arr[i].length() or s.length.
So if you change the for loop to use that as its control, it should solve the index out of bounds exception that you get.
The fix would look like:
for (int j = 0; j < s.length; j++) {
if (s[j] == 'W') {
count++;
}
}

Program that removes duplicated elements and return its new elements and size

My code is almost done but the problem is the returning size it supposed to return the size after the duplicated elements has been removed. it wont output the right size.
import java.util.Scanner;
import java.util.Arrays;
public class Main
{
public static void main (String[] args)
{
int size;
int i;
int j;
Scanner scn = new Scanner(System.in);
System.out.print("Enter the number of elements: ");
size = scn.nextInt();
System.out.println("\n");
int myArray[] = new int [size];
for(i = 0; i < size; i++)
{
System.out.print("Enter value for num["+i+"]: ");
myArray[i] = scn.nextInt();
}
System.out.print("\nThe inputted values are ");
for(i = 0; i < size; i++)
{
System.out.print(" " + myArray[i] + ",");
}
System.out.print("\nDuplicate values ");
for (i = 0; i < myArray.length-1; i++)
{
for (j = i+1; j < myArray.length; j++)
{
if ((myArray[i] == myArray[j]) && (i != j))
{
System.out.print(" " +myArray[j]+ ",");
}
}
}
int length = myArray.length;
length = remove_dupli(myArray,length);
System.out.print("\nThe new values of the array are ");
for(i = 0; i < length; i++)
{
System.out.print(" " +myArray[i]+", ");
}
System.out.println("\nThe new length of the array is: "+array_sort(myArray));
}
is there a problem on this part?
public static int remove_dupli(int myArray[], int n){
if (n==0 || n==1){
return n;
}
int[] temp = new int[n];
int j = 0;
for (int i=0; i<n-1; i++){
if (myArray[i] != myArray[i+1]){
temp[j++] = myArray[i];
}
}
temp[j++] = myArray[n-1];
for (int i=0; i<j; i++){
myArray[i] = temp[i];
}
return j;
}
or this part?
public static int array_sort(int[] myArray) {
int index = 1;
for (int i = 1; i < myArray.length; i++) {
if (myArray[i] != myArray[index-1])
myArray[index++] = myArray[i];
}
return index;
}
}
The output should be:
Enter Number of Elements: 4
Enter value for num[0]: 2
Enter value for num[1]: 2
Enter value for num[2]: 3
Enter value for num[3]: 4
The inputted values are 2,2,3,4
Duplicated values 2,
The new values of the array are 2,3,4
The new length of the array is 3

The process you are using to find the duplicate elements is fine but you are not actually changing the elements in the array , you are just printing the non-duplicate ones, best approach is to change the value of the duplicate elements as a flag and then to find the length of the array after the duplicates have been removed,it will be easy :
for(int i=0;i<array.length;i++){
for(int j=i+1;j<array.length;j++)
{
if((array[i]==array[j]) && i!=j)
System.out.println("duplicate value:"array[j]);
array[j]=-1;
}
}
So, now for the array length after removing the duplicate elements is:
int count=0;
for(int i=0;i<array.length;i++){
if(array[i]!=-1)
count ++;
}

why do I get -1 when i try to delete an element in an array

I checked out the questions that were already posted, but I still couldn't find a solution.
My output for the code is:
Enter the number of integers: 5
Enter 5 integers: 1
2
3
4
5
Enter the number to be deleted: 2
-1
package array;
import java.util.*;
//import java.util.ArrayLists;
public class DeleteFromArray {
public static void main(String[] args) {
int n = 0; // number of integers
int d = 0; // the number to be deleted
int count = 0;
Scanner scan = new Scanner(System.in);
System.out.print("Enter the number of integers: ");
n = scan.nextInt();
if (n <= 0) {
System.out.println("Invalid input");
System.exit(-1);
}
int[] buffer = new int[n];
System.out.print("Enter " + n + " integers: ");
for (int k = 0; k < buffer.length; k++) {
buffer[k] = scan.nextInt();
}
System.out.print("Enter the number to be deleted: ");
d = scan.nextInt();
for (int i = 0; i < buffer.length; i++) {
if (buffer[i] == d) {
for (int j = 0; j < (buffer.length) - 1; j++) {
buffer[j] = buffer[j + 1];
}
count++;
break;
}
}
if(count ==0) {
System.out.println("Element not found!");
}
else {
System.out.print("Element Deleted Successfully..!!");
System.out.print("\nNow the New Array is :\n");
for (int i = 0; i < (buffer.length)-1; i++) {
System.out.println(buffer[i]+ " ");
}
}
scan.close();
}
}

Your for loop
for (int j = 0; j < (buffer.length) - 1; j++) {
buffer[j] = buffer[j + 1];
}
will not work properly because it will replace the value at 0 index with the value at index 1 and so on. What you want to do is just intialize the j=i where i is the index of d. and it will replace this value with the next.
for (int j = i; j < (buffer.length) - 1; j++) {
buffer[j] = buffer[j + 1];
}
Try this loop it will work.

Java: Removing duplicates from a user inputted integer array

Im trying to remove duplicates from a user inputted array using java and am getting an error for a duplicate variable, here is what i have so far:
public class sortedArray {
static int alter(int array[], int n) {
if (n == 0 || n == 1)
return n;
int[] arr = new int[n];
int r = 0;
for (int i = 0; i < n - 1; i++)
if (array[i] != array[i + 1])
arr[r++] = array[i];
arr[r++] = array[n - 1];
for (int i = 0; i < r; i++)
array[i] = arr[i];
return r;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int[] array = new int[49];
int n = array.length;
System.out.print("enter some integers (enter -9999 to stop): ");
for (int i = 0; i < array.length; i++) {
array[i] = input.nextInt();
if (array[i] == -9999) {
break;
}
n = alter(array, n);
for (int i = 0; i < n; i++) //getting error here on the i
System.out.print(array[i] + " ");
}
}
}
Any help would be appreciated.

Your problem is that you are trying to redeclare i inside the first for loop. You need to use another counter variable in your second loop:
for (int i = 0; i < array.length; i++) {
array[i] = input.nextInt();
if (array[i] == -9999) {
break;
}
n = alter(array, n);
for (int j = 0; j < n; j++) //getting error here on the i
System.out.print(array[j] + " ");
}

Trying to Identify the non repeating values from the console and print the non-repeating values to output

I am trying to print the non repeated values when user enter some numbers it should display the numbers which are not duplicate. i am getting all the values and my program is as below
public class Compare {
public static void main(String[] args){
Scanner sc= new Scanner(System.in);
System.out.println("enter the string:");
int[] array = new int[7];
for (int i=0; i<array.length;i++) {
array[i] = Integer.parseInt(sc.nextLine());
}
for (int i = 0; i < array.length; i++) {
boolean found = false;
for (int j = i+1; j < array.length; j++)
if (array[i] == array[j]) {
found = true;
break;
}
if(!found)
System.out.println(array[i]);
}
}
}

Instead of boolean found, take a int count=0 for counting the numbers and print the numbers which have count == 1
Change the code accordingly as shown
for (int i = 0; i < array.length; i++) {
int count=0;
for (int j = 0; j < array.length; j++)
if (array[i] == array[j]) {
count++;
}
if(count==1)
System.out.println(array[i]);
}
Input:
1
2
2
3
3
4
5
Output:
1
4
5

You only have to change two things:
Check the whole array for duplicates. int j = 0 instead of int j = i
Don't compare the the value with itself. Add && i != j to your if condition.
Now your code will work.
Input: 1,2,3,3,4,5,6
Output: 1,2,4,5,6

How about using, HashSet?
It will only contain non duplicate values.

You could do this quicker with a map counting the number of values:
public class Compare {
public static void main(String[] args){
Scanner sc= new Scanner(System.in);
System.out.println("enter the string:");
Map<int, int> values = new HashMap<int, int>();
for (int i=0; i<7;i++) {
value = Integer.parseInt(sc.nextLine());
if (!values.contains(value)) {
values.put(value, 1);
} else {
values.put(value, values.get(value) + 1);
}
}
for (int value : values.keySet()) {
if (values.get(value) == 1) {
System.out.println(value);
}
}
}
}