Find position in an array, need to improve the performance

[Per_]

Hello all,

How can I improve the performance of the code below. I got two array DestArray and strArray. I would like to check if all numbers in DestArray exist in strArray and get the position in the strArray if it exist.

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[hrlngrv]

You're looking for the index of every item in DestArray in strArray? You're not doing anything with them? That is, you're not storing them separately?

You want exact matches? Even if so, if strArray were relatively large, better to sort it in ascending order. Then change your loop to

CORRECTION

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[Per_]

Thanks for the replay! Yes I would like to check if all numbers in the DestArray exist in strArray. I will pull out data from the DestArray that is why I would like to get the row number. The DestArray is quite big around 130000 rows.

I could not get the code to be faster with your code? Maybe I did something wrong.

[hrlngrv]

Is strArray sorted in ascending order?

If there could be duplicates in DestArray, you may want to sort it too, then check if the i_th value equals the (i-1)_th value, and if so you already have the index in strArray.

Sorting and binary search are the only ways to speed up operations like this.

[jindon]

The DestArray is quite big around 130000 rows.

Loop with a dictionary object would be faster
e.g
assuming strArray is a single dimensional array,

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