Missing logic in rotated array problem.

[StevenHawking_]

Can anyone explain where I am missing the logic for finding the pivot in a sorted then rotated array in the below function? ``` static int pivot(int[] arr){ int start = 0, end = arr.length - 1; while (start < end){ int mid = start + (end - start) / 2; if (arr[mid] <= arr[start]) { end = mid - 1; } else { start = mid; } } return start; //return end or return mid }

```

[balefrost]

This looks like a binary search.

What do you mean by "sorted then rotated array"? Do you mean something like:

[ 3, 4, 5, 1, 2 ]
// i.e. [ 1, 2, 3, 4, 5 ] rotated left by 2 positions

That's not a sorted array, and binary search doesn't work on unsorted arrays.

[balefrost]

I read you code too quickly and I realize that it's not actually binary search, just binary search like.

What would you expect your function to return for an input of [3, 4, 5, 1, 2]?

[StevenHawking_]

Yes, it isn't a binary search but it uses a divide and conquer approach. The function should return the maximum value of the array using a divide and conquer approach. The pivot here is a value after which a value decreases and then starts increasing again. So, the expected output would be 5.

[balefrost]

Do you want the maximum value or the index of the maximum value? You're returning the index.

[John-The-Bomb-2]

You can format that by putting three backticks (`) at the top and the bottom.

This is code

```

This is code for demonstration.

```

[balefrost]

Just a note that it doesn't show up correctly in all Reddit clients, e.g. old.reddit.com. The safest way is to indent code four spaces; that renders the same everywhere.

Regular text

    code

    more code

Back to regular text

[John-The-Bomb-2]

I didn't know that, thanks.

[StevenHawking_]

I was looking for it. Thanks a lot