Quicksort - Computer Implementation
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We have sorted the list by observation. However, the computer cannot observe a list; the computer cannot sort by observation. We humans can do that, but the computer cannot.
The computer can have a list (an array and its elements) in memory. The computer can give you a particular element (array value) when you give it the array index of the element. The computer can give you the total length of the array. The computer can return the elements in sequence following the index order.
The computer processes the array, one element at a time. The computer cannot observe or sort by observation. I will now show you my way of implementing the algorithm based on what the computer can do.
The list to sort is same as above, that is:
Q W E R T Y U I O P
We shall use three index variables: i, j and k. The i variable is used to scan the array from the left (start) to the right (end) of the list (or sub-list). The j variable is used to scan the array from the right (end) to the left (start) of the list (or sub-list). The k variable is used for the pivot value. All of these are variables for the index of the same main list (array). Note that index begins at zero and ends at “length of array minus 1.”
Thanks for reading so far; we continue in the second and last part of the series.
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