Using a counter in bubble sort

Question

The problem is to count how many times my bubble sort algorithm switches the places of numbers. I tried to use a variable which increments by one each time, but I think there may be an error with scopes or something similar. Instead of returning a number such as 6 (which means numbers were swapped 6 times), it returns 0, which is what I initialized my variable as. How would I get my program to work?

public static int sort(int arr[]) {
    int length = arr.length;
    int temp;
    int count = 0;
    for (int i = 0; i < (length); i++) {
        for (int j = 1; j < (length); j++) {
            if (arr[j - 1] > arr[j]) {
                temp = arr[j-1];
                arr[j-1] = arr[j];
                arr[j] = temp;
                count++;
            }
        }
    }
    return count;
}

Answer 1

Looks like your algorithm is not optimized because of your for loop condition and initialization. As a result you are comparing an element with itself which is redundant.

Proper approach should be like below:

int yourCounter = 0;
for (int i = 0; i < length; i++)
 for (int j = 1; j < length-i; j++)
   if (arr[j - 1] > arr[j]) {
     //swap code
     //yourCounter++;
   }

your counter should give you proper result then.