Logo Data Structures and Algorithms with Object-Oriented Design Patterns in C++
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Removing Items from a List

The purpose of the Withdraw function is to remove an item from the sorted list. Program gif defines the Withdraw function which takes a reference to an Object.

   program10810
Program: SortedListAsArray Class Withdraw Member Function Definition

The Withdraw function makes use of FindOffset to determine the array index of the item to be removed. Removing an object from position i of an ordered list which is stored in an array requires that all of the objects at positions i+1, i+2, ..., tex2html_wrap_inline61316, be moved one position to the left. The worst case is when i=0. In this case, tex2html_wrap_inline61316 items need to be moved to the left.

Although the Withdraw function is able to make use of FindOffset to locate the position of the item to be removed in tex2html_wrap_inline59891 time, the total running time is dominated by the left shift, which is O(n) in the worst case. Therefore, the running time of Withdraw is O(n).


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