Issue
This is a problem in my textbook for my Java class where the user enters 10 integers. The program is supposed to read all integers and only display the unique numbers (not duplicated) as the output. I am having trouble understanding why my output is not picking up the last unique value in the array (5). Can anyone give some insight to this issue? Any help would be appreciated. (Since we are in the early stages of the class and understanding the language, our assignment is to complete this using a nested loop.)
-The output is: Enter 10 numbers: 1 2 3 2 1 6 3 4 5 2 The number of distinct numbers is 5 The distinct numbers are: 1 2 3 6 4
-When it should be: Enter 10 numbers: 1 2 3 2 1 6 3 4 5 2 The number of distinct numbers is 6 The distinct numbers are: 1 2 3 6 4 5
public class ch7e5{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter 10 numbers: ");
int[] numberArray = new int[10];
//create array for all numbers
int[] distinctArray = new int[10];
//create array for distinct numbers
int distinct = 0;
for (int i = 0; i < 10; i++)
numberArray[i] = input.nextInt();
distinctArray[0] = numberArray[0];
//first value will be distinct
for (int i = 1; i < numberArray.length; i++) {
//loop to go through remaining values in numberArray
boolean exists = false;
//create boolean
for (int j = 0; j < numberArray.length; j++) {
//loop to check if value exists already in distinctArray
if (numberArray[i] == distinctArray[j]) {
exists = true;
break;
//break out of inner loop
}
}
if (exists == false) {
//if value is unique then add it to the distinct array
distinct++;
distinctArray[distinct] = distinctArray[i];
}
}
//}
System.out.println("The number of distinct numbers is " + distinct);
System.out.print("The distinct numbers are: ");
for (int k = 0; k < distinct; k++)
System.out.print(distinctArray[k] + " ");
}
}```
Solution
The error was here
distinct++;
distinctArray[distinct] = distinctArray[i];
1, you should increment distinct
after adding a number to distinctArray
, and 2, you should have done distinctArray[distinct] = numberArray[i]
. Right now, you're just putting what is possibly a 0
into distinctArray[distinct]
.
A shorter way to do it would be this
int[] distinctArray = Arrays.stream(numberArray).distinct().toArray();
System.out.println("The number of distinct numbers is " + distinctArray.length);
System.out.print("The distinct numbers are: ");
for (int d : distinctArray) System.out.print(d + " ");
Output:
Enter 10 numbers: 1 2 3 2 1 6 3 4 5 2
The number of distinct numbers is 6
The distinct numbers are: 1 2 3 6 4 5
Answered By - user