#binary search help

1 messages · Page 1 of 1 (latest)

severe horizon
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hello again guys... back here again, running into more problems :(

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so for anyone who doesn't know already - it's a turn-based game between an AI and the player to try and guess where is the correct card

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If the correct card happens to be in the second half of the card deck, it works wonderfully fine!

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But if it's on the first half, it starts doing crazy things: the limits (the range of the search) is set correctly, but 1st- it ignores the change of turns and does the search automatically - and it doesn't search through the first half, but through the second

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It's driving me crazy

torpid geyser
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It seems like you have a couple different things going on, based on your text here, compared to your title. As for your title, re Binary Search, your collection needs to be sorted. I'm not sure if it is based on your code.

severe horizon
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The collection is sorted, it gave me a headache because i used // allCards = allCards.OrderBy(x => x.cardOrder).ToList(); but it suddenly stopped working, so i just ordered the cards in the unity editor

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i know it's not the best answer to that problem... but something happened and the cards didn't want to be sorted haha

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right now- the cards are sorted exactly the way i want them and the code can detect it

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also on another script i have set the class Cards with these 3 variables public bool Winner; public bool isTurned; public int cardOrder;

torpid geyser
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Ok. I would double check that the cards are actually sorted during runtime, before you call whatever function it is (print it out or something).

Then it would just be a standard binary search algo:

        int left = 0, right = nums.Length-1;
        while (left <= right)
        {
            int mid = left + (right - left) / 2;
            if (nums[mid] == target)
                return mid;
            else if (target > nums[mid])
                left = mid + 1;
            else
                right = mid - 1;
        }

nums being your collection, and returning mid which is the index, or you could make it nums[mid for the value.

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If it's not going into the right function based on whatever turn, then that's something you need to figure out. Break it down into small problems, resolve one at a time.

severe horizon
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i've debugged a ton of things, asked for help to classmates... nothing happens

torpid geyser
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I guess I'm confused here; does your project work fine when you remove BS?

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Can you just run it linearly?

severe horizon
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yep

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my linear function works perfectly

torpid geyser
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Oh ok, so then 1) your array is not sorted 2) your algo is wrong.

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It should be fairly simple to debug from there.

severe horizon
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sorry it's in spanish, but I ran the game again and as you can see, the cards are sorted the way i want, from 0 to 9

image.png
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so the problem is the algorithm :[

torpid geyser
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Yeah, I mean i honestly have no clue why you're looping forwards, and then looping backwards lol

torpid geyser
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Your code is not even near that.

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I think you may be misunderstanding how Binary Search operates.

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I can't even understand your code in that section, tbh.

severe horizon
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i understand binary search and my code is pretty simple afaik, it's pretty much the same except that i'm working with classes and not with ints, and also changing turns and cards