Program that deletes one integer (or more if there's duplicates) from an array by it's val-CodePudding

I need to write a program, which deletes a number of elements from an int array that are equal to some int value. Eventually I should get an array that isn't bigger than the initial one.

I mustn't use lists or any methods that do the deletion directly.

I tried to do this this way and I can't trace the flaw. I suppose, it should be in the last "for" construction but I'm not sure.


import java.util.Arrays;
import java.util.Scanner;

public class App {
public static void main(String\[\] args) {
Scanner scan = new Scanner(System.in);
System.out.print("Array size: ");
int sizeInput = scan.nextInt();

        int[] original = new int[sizeInput];
    
        System.out.print("Array itself: ");
        for (int i = 0; i < sizeInput; i  ) {
            original[i] = scan.nextInt();
        }
    
        System.out.println("Number to be deleted: ");
        int dNumber = scan.nextInt();
    
        int[] newArr = new int[original.length];
    
        for (int i = 0; i < original.length - 1; i  ) {
            int sum = 0;
            if (original[i] == dNumber) {
                newArr[i] = original[i   1];
                sum = sum   1;
            } else if (original[i] != dNumber) {
                newArr[i] = original[i   sum];
            } 
        }
        System.out.println(Arrays.toString(newArr));
    }

}

and here's what I got in my console eventually:

Array size: 5
Array itself: 1 2 3 4 5
Number to be deleted: 2
\[1, 3, 3, 4, 0\]

You see? In the output I get the second "3" for some reason and I also don't get why there's no last element of the initial array.

Please, explain what wrote wrong so that my code doesn't solve the problem. And please explain ho can I solve It. Thanks!

CodePudding user response：

You need a position int for the new array, so you go further only when you set a new value

int[] original = {1, 2, 3, 4, 5};
int dNumber = 2;

int[] newArr = new int[original.length];
int j = 0;
for (int val : original) {
    if (val != dNumber) {
        newArr[j] = val;
        j  ;
    }
}
newArr = Arrays.copyOf(newArr, j); // truncate
System.out.println(Arrays.toString(newArr));
// [1, 3, 4, 5]