Binary Search by Sergey #1
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| int mid = (right-left)/2; | ||
| if (left>=right) return -1; | ||
| if (element < array[mid]) { | ||
| return find(array, element, left, mid); |
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Why do you include mid element in recursive call? I think it's obsolete here and in another branch.
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@sergeyenin , I misunderstood @den-sergeyev, so to make it clear what he meant is:
return find(array, element, left, mid-1);
otherwise you will get infinite recursion in some cases.
| return find(array, element, left, mid); | ||
| } | ||
| else if (element > array[mid]) { | ||
| return find(array, element, mid, right); |
|
@den-sergeyev @tarasevich @egorhm more comments? |
| @@ -1,5 +1,43 @@ | |||
| public class BinarySearch { | |||
| public static int find(int[] array, int element) { | |||
| int iterativeResult = findIterative(array, element); | |||
| int reccursiveResult = findReccursive(array, element, 0, array.length-1); | |||
| int resultValue = (iterativeResult == reccursiveResult) ? iterativeResult : -1; | |||
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i'd suggest to return something else in this case, e.g. -2.
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I suppose returning -1 means, that the Binary search have not got correct answer for the questions - what is the element`s positions.
In a case, when Iterative and Recursive functions are returning the different answers - it means that we have not correct answer.
I dont think that return special code is a good idea, since it demands additional contract besides standard one.
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@sergeyenin, I think you can't distinguish two cases here:
- IterativeResult returns
-1and it's correct answer. - IterativeResult and recursiveResult differs, hence something is wrong but you still returns
-1.
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I suppose, 2-nd case means, that we have not found the correct answer, which more or less equals to 1-st case.
Anyway, it is a tradeoff between returning more rich information and extending the contract.
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@den-sergeyev understands my point :)
@sergeyenin , you will not violate the "contract" if your code is correct ;) and if your code is incorrect it's already violation of the "contract". It's better to extend a contract than to hide mistakes from unit testing.
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@tarasevich me either, but I don`t see a lot advantages, really)
@den-sergeyev @egorhm @tarasevich what do you think?