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Finding Minimum and Maximum

What you need to know

You must be able to describe, exemplify and implement arrays of records

Explanation

The find minimum (find-min) and find maximum (find-max) algorithms are very similar, only differing in whether they use the < or > sign.

These algorithms would only work on arrays of integers or real numbers (you can’t find the “maximum name” from an array of strings).

For example, below is an array of 10 integers:

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To find the maximum (highest) value, we would look through the list one-by-one:

  • The first value is 33. We don’t yet know any other values, so 33 must be the highest we’ve found.

  • The next value is 12. That is less than 33, so we ignore it (it isn’t higher).

  • The next value is 46. This is higher than 33 (the highest we’ve found so far), so becomes the new highest.

  • The next value is 18. This is lower than 46 (the current highest found), so we ignore it…

On that basis, we would find that 49 (element 6) is the highest value in the array.

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Declare a maximum variable, and set it to the first item in the array (e.g. 33)

Loop for each element in the array

    If number(counter) > maximum

        Set maximum to number(counter)

    End if

End for loop

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Declare a minimum variable, and set it to the first item in the array (e.g. 33)

Loop for each element in the array

    If number(counter) < maximum

        Set minimum to number(counter)

    End if

End for loop